TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP81-01043R000500080007-7
• Release Decision: RIPPUB
• Original Classification: U
• Document Page Count: 64
• Document Creation Date: December 22, 2016
• Document Release Date: July 13, 2010
• Sequence Number: 7
• Publication Date: November 23, 1956
• Content Type: REPORT

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STAT
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 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN
OF ANTENNAS FOR SCATTER
John Granlund
Group 33
Technical Report No. 135
23 November 1956
ABSTRACT
Unlike the signal received over aline-of?sight h nhens ties thatgmas berdescribed
receiving site from a continuum of directions w-t Y
by a directional pattern similar to an antenna pattern. This report shows how the
mean signal power available at the terminals of a receiving antenna may be ex-
pressed in terms of the antenna pattern and of a pattern of incoming power density.
Methods of measuring the power?densitypattern at the receiving site are discussed.
Designs maximizing the available power are obtained for two rather general types
of antenna when they are illuminated by arbitrary power?density patterns. Numerical
results, obtained for an assumed Gaussian?shaped power?sensity pattern, suggest
that only a very small increase in available power may be obtained by readjusting
the pattern of an antenna that was initially adjusted to have maximum plane?wave
gain in the direction of maximum power density.
A large array of small antennas may be subject to "gain loss" but, if the connec-
tions between array elements are allowed to vary in time at the fading rate, the
array will not exhibit "gain loss." Appropriate electronic circuitry for the inter
connections is discussed.
MASSACHUSETTS INSTITUTE OF TECHNOLOGY
LINCOLN LABORATORY LEXINGTON, MASSACHUSETTS
UNCLASSIFIED
STAT
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 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
UNCLASSIFIED
Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
 Sanitized Copy Approved for Release 2010/07/13 :CIA-RDP81-010438000500080007-7
UNCLASSIFIED
TOPICS IN THE DESIGN OF ANTENNAS FOR SCATTER
I. INTRODUCTION
Practical communication links utilizing the weak, fluctuating scatter signals received from
a remote transmitter have been demonstrated.1 Unlike signals received over a short line-of-
sight path, these scatter signals arrive at the receiving site from a continuum of directions with
intensities that may be described by a directional pattern similar to an antenna pattern. This
spread in the directions of arrival of the signal components gives rise to a phenomenon that has
misleadingly been called "gain loss": The strengths of scatter signals from a remote trans-
mitter, received on adjacent, dissimilar antennas, are not in the same proportion as the plane-
wave gains of the antennas.
As suggested by Schott,2 the mean signal power available at the terminals of a receiving
antenna is proportional to the sum (or integral) over all directions of the pattern of incoming
power density weighted by the antenna pattern. In arriving at this result, Schott makes the
plausible assumption that the plane-wave components of the signal arriving from different direc-
tions are uncorrelated. This assumption, which is also made here, is implicit in the concept of
a pattern of power density; the assumption is discussed in greater detail in the next section.
The aim of this report is to provide a method for arriving at a "best" antenna design for
the reception of scatter signals. Certainly the "best" antenna should deliver the "greatest"
signal strength to its associated receiver but, since scatter signals are subject to fading, the
choice of a "greatest" signal implies a criterion of measurement. Also, in general, the larger
the antenna, the greater the signal it will deliver. In the sense of this report, the optimum re-
ceiving antenna is that stationary structure of a given size which delivers maxirnum mean signal
power to a matched load.
Although the pattern of incoming power density gives necessary and sufficient signal data
for the design of an optimum receiving antenna, the shape of this pattern depends on the shape
of the transmitting antenna pattern as well as on the behavior of the scattering mechanism. In
other words, a detailed description of the scattering mechanism itself would be necessary for
the simultaneous optimization of both transmitting and receiving antennas. Such a description
is beyond the scope of this report. Nevertheless, the remainder of this introductory section is
given to an elementary discussion of the effects that the transmitting and receiving antenna pat-
terns may have on the received signal power.
Following a simplified version of the Booker-Gordon model of the scattering mechanism 3
let us suppose that the transmitting antenna emits power uniformly in a circular cone having a
small angle 9t, as in Fig. 4. Similarly, let the receiving antenna accept power uniformly only
in a cone having a small angle 8r. Suppose that the region above the surface of the earth is
entirely uniform except for some subregion having a volume V, where scattering takes place.
Suppose that each volume element, pV, of V scatters power isotropically, so that KpV watts
per unit solid angle are scattered when the volume element is illuminated with unit power density
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