US3757336A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Antenna direction control system
Assignee: Raytheon Co
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Filing: 1970-07-02
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Granted: 1973-09-04
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Expires: 1990-07-02
Abstract
Abstract A satellite communications system comprises signal tracking for a directional antenna by detecting any directional error of the antenna relative to a pilot station, or predetermined offset angle therefrom, to provide phase modulated error signals which are combined with frequency modulated pilot signals radiated by the pilot station in order to pass composite error and pilot signals through a single receive channel including a rotary joint coupler connecting a spinning section and a despun antenna section of a spin-stabilized satellite. Any directional error of the despun antenna about the spin axis of a spinning satellite results in sum and difference signals being produced in the receive feeds of the antenna wherein the magnitude of the difference signal is proportional to the angle of deviation of the antenna pointing direction and the pilot station. The difference signal is phase modulated in an over-coupled, doubletuned, directional filter and combined with the sum signal to produce a composite signal which exhibits amplitude modulation in synchronism with the frequency modulation of the sum signal. The amplitude modulation index is proportional to the difference signal and hence the directional error; and the phase of the amplitude modulation relative to the phase of the frequency modulation indicates the sign of the error. After passing through the rotary coupler, the envelope of the AM signal is detected and compared in a phase detector, with a reference signal derived from the FM of the composite signal. The output of the phase detector is the directional error signal which provides a tracking signal for controlling a despin motor to correct the error in pointing of the antenna.
Inventors
- 👤 H Rosen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:54
CPC Classifications
G; G01; G01S; G01S3/00; G01S3/02; G01S3/14; G01S3/28; G01S3/32; G01S3/325
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
231 words
In a communication system, the combination comprising: a directional antenna for receiving a radiated frequency modulated signal from a signal source, said signal having a period for peak-to-peak frequency deviations, said antenna having antenna feeds responsive to the radiated signal received to produce individual signal outputs including individual signal outputs of different magnitude whenever the pointing direction of the antenna deviates from the direction of said radiated signal; means coupled to said antenna feeds, said means including a sum arm responsive to individual signal outputs to add said signal outputs to produce a sum signal and a difference arm responsive to individual signal outputs of different magnitudes to produce a difference signal having a magnitude corresponding to the degree of deviation of the pointing direction of said antenna from the direction of said source; frequency selective delay means having a band-width corresponding approximately to said peak-to-peak frequency deviations of said radiated signal, said delay means being responsive to said difference signal to produce a phase modulated signal having a magnitude corresponding to said degree of deviation of said antenna and periodic phase reversals wherein the period of Said phase reversals corresponds to the period for peak-to-peak frequency deviation of the radiated signal; and means for combining said sum signal and phase modulated signal to provide a composite signal exhibiting amplitude modulation including said periodic phase reversals of said phase modulated signals.
Claim 2
Dependent Claim
231 words
In a communication system, the combination comprising: a directional antenna for receiving a radiated frequency modulated signal from a signal source, said signal having a period for peak-to-peak frequency deviations, said antenna having antenna feeds responsive to the radiated signal received to produce individual signal outputs including individual signal outputs of different magnitude whenever the pointing direction of the antenna deviates from the direction of said radiated signal; means coupled to said antenna feeds, said means including a sum arm responsive to individual signal outputs to add said signal outputs to produce a sum signal and a difference arm responsive to individual signal outputs of different magnitudes to produce a difference signal having a magnitude corresponding to the degree of deviation of the pointing direction of said antenna from the direction of said source; frequency selective delay means having a band-width corresponding approximately to said peak-to-peak frequency deviations of said radiated signal, said delay means being responsive to said difference signal to produce a phase modulated signal having a magnitude corresponding to said degree of deviation of said antenna and periodic phase reversals wherein the period of Said phase reversals corresponds to the period for peak-to-peak frequency deviation of the radiated signal; and means for combining said sum signal and phase modulated signal to provide a composite signal exhibiting amplitude modulation including said periodic phase reversals of said phase modulated signals.
Claim 3
Dependent Claim
47 words
The combination according to claim 1 which further includes means for detecting the amplitude of said composite signal to provide an antenna directional error signal corresponding in magnitude to the degree of deviation of the pointing direction of the antenna from the direction of said radiated signal.
Claim 4
Dependent Claim
60 words
The combination according to claim 1 in which said means coupled to said antenna feeds includes means responsive to a change in pointing direction of the antenna which crosses over the direction of said radiated signal to produce a reversal in polarity of said difference signal and a corresponding reversal in polarity of said amplitude modulation of said composite signal.
Claim 5
Dependent Claim
51 words
The combination according to claim 3 which further includes means responsive to said composite signal for producing an error signal having a magnitude proportional to said degree of directional deviation of said antenna and polarity corresponding to the pointing direction of the antenna relative to the direction of the radiated signal.
Claim 6
Dependent Claim
91 words
The combination according to claim 4 which further comprises a spin-stabilized vehicle having a predetermined spin axis transverse to the direction of a source of said radiated signal including a spinning section, a despun section, and means including a rotary joint coupler and a despin motor for controlling the pointing of said directional antenna disposed on said despun section about said spin axis, said despin motor being responsive to said error signal to maintain the pointing direction of the antenna about the spin axis toward the source of said radiated signal.
Claim 7
Dependent Claim
91 words
The combination according to claim 5 in which said directional antenna comprises antenna feed means including two feed horns and a single parabolic reflector, and said feed horns are offset from the axis of said reflector to provide receive signal outputs of different magnitudes whenever the pointing direction of the antenna is different from the direction of said source of radiated signals and the magnitude of the difference of said receive signal outputs is proportional to the angle between the pointing direction and the direction of the source of radiated signals.
Claim 8
Dependent Claim
35 words
The combination according to claim 6 in which said feed horns are disposed to produce difference signals of opposite polarity corresponding to the antenna pointing directions on either side of said source of radiated signal.
Claim 9
Independent Claim
171 words
A system for multiplexing a plurality of frequency modulated signals to provide a composite signal exhibiting amplitude modulation as a function of magnitude of at least one of the frequency modulated signals having a frequency modulation rate comprising: frequency selective delay means capable of producing phase reversals between peak frequency deviations of frequency modulation and responsive to at least one of said plurality of frequency modulated signals capable of varying in magnitude, to phase modulate said latter signal including periodic phase reversals at the frequency modulated rate; combining means responsive to said phase modulated signal and another of said plurality of frequency modulated signals to produce a composite signal exhibiting amplitude modulation wherein the index of amplitude modulation is a function of the magnitude of said frequency modulated signal capable of varying in magnitude; and one of said plurality of frequency modulated signals and said another of said plurality of frequency modulated signals have the same modulation rate to provide periodic phase reversals of the amplitude modulation of said composite signal.
Claim 10
Independent Claim
171 words
A system for multiplexing a plurality of frequency modulated signals to provide a composite signal exhibiting amplitude modulation as a function of magnitude of at least one of the frequency modulated signals having a frequency modulation rate comprising: frequency selective delay means capable of producing phase reversals between peak frequency deviations of frequency modulation and responsive to at least one of said plurality of frequency modulated signals capable of varying in magnitude, to phase modulate said latter signal including periodic phase reversals at the frequency modulated rate; combining means responsive to said phase modulated signal and another of said plurality of frequency modulated signals to produce a composite signal exhibiting amplitude modulation wherein the index of amplitude modulation is a function of the magnitude of said frequency modulated signal capable of varying in magnitude; and one of said plurality of frequency modulated signals and said another of said plurality of frequency modulated signals have the same modulation rate to provide periodic phase reversals of the amplitude modulation of said composite signal.
Claim 11
Independent Claim
163 words
A system for multiplexing a plurality of frequency modulated signals to provide a composite signal eXhibiting amplitude modulation as a function of magnitude of at least one of the frequency modulated signals having a frequency modulation rate comprising: frequency selective delay means capable of producing phase reversals between peak frequency deviations of frequency modulation and responsive to at least one of said plurality of frequency modulated signals capable of varying in magnitude, to phase modulate said latter signal including periodic phase reversals at the frequency modulated rate; combining means responsive to said phase modulated signal and another of said plurality of frequency modulated signals to produce a composite signal exhibiting amplitude modulation wherein the index of amplitude modulation is a function of the magnitude of said frequency modulated signal capable of varying in magnitude; and said plurality of frequency modulated signals are signals of microwave frequency and said frequency selective delay means comprises a microwave directional filter, double-tuned to said peak frequency deviations.
Claim 12
Independent Claim
163 words
A system for multiplexing a plurality of frequency modulated signals to provide a composite signal eXhibiting amplitude modulation as a function of magnitude of at least one of the frequency modulated signals having a frequency modulation rate comprising: frequency selective delay means capable of producing phase reversals between peak frequency deviations of frequency modulation and responsive to at least one of said plurality of frequency modulated signals capable of varying in magnitude, to phase modulate said latter signal including periodic phase reversals at the frequency modulated rate; combining means responsive to said phase modulated signal and another of said plurality of frequency modulated signals to produce a composite signal exhibiting amplitude modulation wherein the index of amplitude modulation is a function of the magnitude of said frequency modulated signal capable of varying in magnitude; and said plurality of frequency modulated signals are signals of microwave frequency and said frequency selective delay means comprises a microwave directional filter, double-tuned to said peak frequency deviations.
Claim 13
Independent Claim
183 words
A system for multiplexing a plurality of frequency modulated signals to provide a composite signal exhibiting amplitude modulation as a function of magnitude of at least one of the frequency modulated signals having a frequency modulation rate comprising: frequency selective delay means capable of producing phase reversals between peak frequency deviations of frequency modulation and responsive to at least one of said plurality of frequency modulated signals capable of varying in magnitude, to phase modulate said latter signal including periodic phase reversals at the frequency modulated rate; combining means responsive to said phase modulated signal and another of said plurality of frequency modulated signals to produce a composite signal exhibiting amplitude modulation wherein the index of amplitude modulation is a function of the magnitude of said frequency modulated signal capable of varying in magnitude; and said one of said frequency modulated signals comprises a difference signal and said another of said plurality of frequency modulated signals comprises a sum signal, and said system further includes means for deriving sum and difference signals from individual frequency modulated signals having the same frequency modulation rate.
Claim 14
Independent Claim
183 words
A system for multiplexing a plurality of frequency modulated signals to provide a composite signal exhibiting amplitude modulation as a function of magnitude of at least one of the frequency modulated signals having a frequency modulation rate comprising: frequency selective delay means capable of producing phase reversals between peak frequency deviations of frequency modulation and responsive to at least one of said plurality of frequency modulated signals capable of varying in magnitude, to phase modulate said latter signal including periodic phase reversals at the frequency modulated rate; combining means responsive to said phase modulated signal and another of said plurality of frequency modulated signals to produce a composite signal exhibiting amplitude modulation wherein the index of amplitude modulation is a function of the magnitude of said frequency modulated signal capable of varying in magnitude; and said one of said frequency modulated signals comprises a difference signal and said another of said plurality of frequency modulated signals comprises a sum signal, and said system further includes means for deriving sum and difference signals from individual frequency modulated signals having the same frequency modulation rate.
Claim 15
Dependent Claim
53 words
The system according to claim 10 which further includes directional antenna means including feed means responsive to a radiated frequency modulated signal for producing separate frequency modulated signal outputs including signal outputs of different magnitude whenever the pointing direction of said directional antenna means is different from the direction of said radiated signal.
Claim 16
Dependent Claim
64 words
The system according to claim 10 in which the source of said radiated signal is the desired pointing direction of said antenna means and said means for deriving sum and difference signals is responsive to deviations in the direction of the antenna to opposite sides of said source to produce a phase reversal of said difference signal and amplitude modulation of said composite signal.
Claim 17
Dependent Claim
297 words
A control system for aiming a directional antenna, disposed on a despun section of a spin-stabilized vehicle, toward a pilot station source of radiated frequency modulated signals comprising: a directional antenna including feed means responsive to an angle of directional error of said antenna relative to the direction of said pilot station to produce individual signals of different magnitude wherein the difference in magnitude corresponds to the magnitude of the error angle; means responsive to said individual signals for producing sum and difference signals including a difference signal having a magnitude proportional to the error angle and polarity corresponding to the direction of aiming of the antenna relative to the pilot station; means for phase modulating said difference signal to produce periodic phase reversals of said difference signal at the frequency modulation rate of said piLot signals; combining means for combining the sum and phase modulated difference signals to produce a composite signal exhibiting amplitude modulation in synchornism with the frequency modulation of the pilot signal wherein the index of amplitude modulation is proportional to the magnitude of the difference signal and the phase of the composite signal is determined by the polarity of the difference signal; rotary coupling means including a coaxial cable for coupling said composite signal from the combining means disposed on the despun section to the spinning section of said vehicle, means disposed on said despun section and coupled to said rotary coupling means for detecting the index of amplitude modulation and phase of said amplitude modulation relative to said frequency modulation to produce an error signal having a magnitude proportion to the error angle; and means including a despin motor responsive to said error signal to control the despinning of said despun section to maintain said antenna aimed toward said pilot station.
Claim 18
Dependent Claim
297 words
A control system for aiming a directional antenna, disposed on a despun section of a spin-stabilized vehicle, toward a pilot station source of radiated frequency modulated signals comprising: a directional antenna including feed means responsive to an angle of directional error of said antenna relative to the direction of said pilot station to produce individual signals of different magnitude wherein the difference in magnitude corresponds to the magnitude of the error angle; means responsive to said individual signals for producing sum and difference signals including a difference signal having a magnitude proportional to the error angle and polarity corresponding to the direction of aiming of the antenna relative to the pilot station; means for phase modulating said difference signal to produce periodic phase reversals of said difference signal at the frequency modulation rate of said piLot signals; combining means for combining the sum and phase modulated difference signals to produce a composite signal exhibiting amplitude modulation in synchornism with the frequency modulation of the pilot signal wherein the index of amplitude modulation is proportional to the magnitude of the difference signal and the phase of the composite signal is determined by the polarity of the difference signal; rotary coupling means including a coaxial cable for coupling said composite signal from the combining means disposed on the despun section to the spinning section of said vehicle, means disposed on said despun section and coupled to said rotary coupling means for detecting the index of amplitude modulation and phase of said amplitude modulation relative to said frequency modulation to produce an error signal having a magnitude proportion to the error angle; and means including a despin motor responsive to said error signal to control the despinning of said despun section to maintain said antenna aimed toward said pilot station.
References Cited (Backward Citations)
US3340532A
Cited
US3348168A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-03 | 1977-03-05 | 1977-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-03 | 1981-03-05 | 1981-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-03 | 1985-03-05 | 1985-09-04 | $7700.00 | Window Closed / Lapsed |