Patent US3882413A successfully refreshed from Google Patents.
US3882413A
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US
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Microwave signal source stabilized by automatic frequency and phase control loops
Assignee: Westinghouse Electric Corp
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Filing: 1973-07-30
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Granted: 1975-05-06
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Expires: 1993-07-30
Abstract
Abstract A microwave signal source and method for providing a microwave output signal having an improved noise characteristic are disclosed. The desirable signal characteristic is obtained by generating an oscillator frequency control signal, preferably through the use of an automatic frequency control (AFC) loop, and by modifying the frequency control signal in response to a vernier phase control signal, preferably from an automatic phase control (APC) loop, in such a manner that desirable characteristics of both signals are employed in producing the microwave output signal.
Inventors
- 👤 Iii Daniel J Healey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:29
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/16; H03L7/20; H03L7/02; H03L7/04; H03L7/08; H03L7/10; H03L7/113
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
189 words
A method for controlling the frequency of a signal comprising the steps of: generating a first signal having a noise power density below a predetermined level at Fourier frequencies above a first Fourier frequency, the frequency of the first signal being automatically controlled about a predetermined center frequency by a frequency control signal provided by a frequency discriminator in an automatic frequency control loop; generating a second signal having a frequency approximately equal to said center frequency and having a noise power density below said predetermined level at Fourier frequencies below a second Fourier frequency higher than the first Fourier frequency; generating a phase control signal responsively to a phase comparison between the first and second signals; modifying the frequency control signal in response to the phase control signal at Fourier frequencies below the second Fourier frequency; controlling the frequency of the first signal in response to the modified frequency control signal; modifying the first signal by means of a passive resonant frequency determining element, said passive resonant frequency determining element being part of said frequency control loop; and, providing said modified first signal as an oscillator output signal.
Claim 2
Independent Claim
189 words
A method for controlling the frequency of a signal comprising the steps of: generating a first signal having a noise power density below a predetermined level at Fourier frequencies above a first Fourier frequency, the frequency of the first signal being automatically controlled about a predetermined center frequency by a frequency control signal provided by a frequency discriminator in an automatic frequency control loop; generating a second signal having a frequency approximately equal to said center frequency and having a noise power density below said predetermined level at Fourier frequencies below a second Fourier frequency higher than the first Fourier frequency; generating a phase control signal responsively to a phase comparison between the first and second signals; modifying the frequency control signal in response to the phase control signal at Fourier frequencies below the second Fourier frequency; controlling the frequency of the first signal in response to the modified frequency control signal; modifying the first signal by means of a passive resonant frequency determining element, said passive resonant frequency determining element being part of said frequency control loop; and, providing said modified first signal as an oscillator output signal.
Claim 3
Dependent Claim
52 words
The method of claim 1 wherein the frequency control signal is generated by: shifting the phase of a portion of the first signal by a fixed amount to provide a phase shifted first signaL; and, comparing the phase of said modified first signal to the phase of the phase shifted first signal.
Claim 4
Independent Claim
249 words
A method for controlling the frequency of a signal comprising the steps of: generating a first signal having a noise power density below a predetermined level at Fourier frequencies above a first Fourier frequency, the frequency of the first signal being automatically controlled about a predetermined center frequency by a frequency control signal provided by a frequency discriminator in an automatic frequency control loop; generating a second signal having a frequency approximately equal to said center frequency and having a noise power density below said predetermined level at Fourier frequencies below a second Fourier frequency higher than the first Fourier frequency; generating a phase control signal responsively to a phase comparison between the first and second signals; modifying the frequency control signal in response to the phase control signal at Fourier frequencies below the second Fourier frequency; controlling the frequency of the first signal in response to the modified frequency control signal; and wherein the frequency control signal is generated by: applying the first signal to a resonant, frequency determining element to generate a frequency reference signal; shifting the phase of a portion of the first signal by a fixed amount to provide a phase shifted first signal; comparing the phase of the reference signal to the phase of the phase shifted first signal; and wherein the frequency control signal is modified by the phase control signal by shifting the phase of the phase shifted first signal by an amount related to the magnitude of the phase control signal.
Claim 5
Independent Claim
249 words
A method for controlling the frequency of a signal comprising the steps of: generating a first signal having a noise power density below a predetermined level at Fourier frequencies above a first Fourier frequency, the frequency of the first signal being automatically controlled about a predetermined center frequency by a frequency control signal provided by a frequency discriminator in an automatic frequency control loop; generating a second signal having a frequency approximately equal to said center frequency and having a noise power density below said predetermined level at Fourier frequencies below a second Fourier frequency higher than the first Fourier frequency; generating a phase control signal responsively to a phase comparison between the first and second signals; modifying the frequency control signal in response to the phase control signal at Fourier frequencies below the second Fourier frequency; controlling the frequency of the first signal in response to the modified frequency control signal; and wherein the frequency control signal is generated by: applying the first signal to a resonant, frequency determining element to generate a frequency reference signal; shifting the phase of a portion of the first signal by a fixed amount to provide a phase shifted first signal; comparing the phase of the reference signal to the phase of the phase shifted first signal; and wherein the frequency control signal is modified by the phase control signal by shifting the phase of the phase shifted first signal by an amount related to the magnitude of the phase control signal.
Claim 6
Independent Claim
282 words
A method for controlling the frequency of a signal comprising the steps of: generating a first signal having a noise power density below a predetermined level at Fourier frequencies above a first Fourier frequency, the frequency of the first signal being automatically controlled about a predetermined center frequency by a frequency control signal provided by a frequency discriminator in an automatic frequency control loop; generating a second signal having a frequency approximately equal to said center frequency and having a noise power density below said predetermined level at Fourier frequencies below a second Fourier frequency higher than the first Fourier frequency; generating a phase control signal responsively to a phase comparison between the first and second signals; modifying the frequency control signal in response to the phase control signal at Fourier frequencies below the second Fourier frequency; controlling the frequency of the first signal in response to the modified frequency control signal; and wherein the frequency control signal is generated by: applying the first signal to a resonant, frequency determining element to generate a frequency reference signal; shifting the phase of a portion of the first signal by a fixed amount to provide a phase shifted first signal; comparing the phase of the reference signal to the phase of the phase shifted first signal; and wherein the frequency control signal is modified by the phase control signal only at Fourier frequencies lower than the second Fourier frequency by: filtering the phase control signal to remove all components having frequencies above a predetermined frequency lower than the second Fourier frequency; and shifting the phase of the portion of the first signal by an amount related to the magnitude of the phase control signal.
Claim 7
Independent Claim
282 words
A method for controlling the frequency of a signal comprising the steps of: generating a first signal having a noise power density below a predetermined level at Fourier frequencies above a first Fourier frequency, the frequency of the first signal being automatically controlled about a predetermined center frequency by a frequency control signal provided by a frequency discriminator in an automatic frequency control loop; generating a second signal having a frequency approximately equal to said center frequency and having a noise power density below said predetermined level at Fourier frequencies below a second Fourier frequency higher than the first Fourier frequency; generating a phase control signal responsively to a phase comparison between the first and second signals; modifying the frequency control signal in response to the phase control signal at Fourier frequencies below the second Fourier frequency; controlling the frequency of the first signal in response to the modified frequency control signal; and wherein the frequency control signal is generated by: applying the first signal to a resonant, frequency determining element to generate a frequency reference signal; shifting the phase of a portion of the first signal by a fixed amount to provide a phase shifted first signal; comparing the phase of the reference signal to the phase of the phase shifted first signal; and wherein the frequency control signal is modified by the phase control signal only at Fourier frequencies lower than the second Fourier frequency by: filtering the phase control signal to remove all components having frequencies above a predetermined frequency lower than the second Fourier frequency; and shifting the phase of the portion of the first signal by an amount related to the magnitude of the phase control signal.
Claim 8
Independent Claim
138 words
A method for controlling the frequency of an output signal from a voltage controlled oscillator with a high degree of stability comprising the steps of: generating a phase control signal related in amplitude to the phase relationship between the voltage controlled oscillator output signal and a crystal controlled oscillator output sIgnal; shifting the phase of a portion of the voltage controlled oscillator output signal by a predetermined fixed amount modified by a variable amount related to the amplitude of the phase control signal; generating a frequency control signal related in amplitude to the phase relationship between the phase shifted voltage controlled oscillator output signal and an output signal from a frequency determining element excited by the voltage controlled oscillator output signal; and, controlling the frequency of the voltage controlled oscillator output signal responsively to the frequency control signal.
Claim 9
Independent Claim
138 words
A method for controlling the frequency of an output signal from a voltage controlled oscillator with a high degree of stability comprising the steps of: generating a phase control signal related in amplitude to the phase relationship between the voltage controlled oscillator output signal and a crystal controlled oscillator output sIgnal; shifting the phase of a portion of the voltage controlled oscillator output signal by a predetermined fixed amount modified by a variable amount related to the amplitude of the phase control signal; generating a frequency control signal related in amplitude to the phase relationship between the phase shifted voltage controlled oscillator output signal and an output signal from a frequency determining element excited by the voltage controlled oscillator output signal; and, controlling the frequency of the voltage controlled oscillator output signal responsively to the frequency control signal.
Claim 10
Dependent Claim
25 words
The method of claim 5 including the step of filtering the phase control signal to remove components having a frequency above a predetermined Fourier frequency.
Claim 11
Dependent Claim
206 words
Apparatus for controlling the frequency of a periodic signal comprising: means for generating a first signal controllable in frequency about a predetermined center frequency, said first signal having a noise power density below a predetermined level at Fourier frequencies above a first Fourier frequency; means for generating a second signal having a frequency approximately equal to said center frequency and having a noise power density below said predetermined level at Fourier frequencies below a second Fourier frequency higher than the first Fourier frequency; means for comparing the first and second signals in phase and for generating a phase control signal responsively to the phase comparison between the first and second signals; means for generating a frequency control signal responsively to the first signal; means for modifying the frequency control signal in response to the phase control signal at Fourier frequencies below the second Fourier frequency; means for controlling the frequency of the first signal in response to the modified frequency control signal; said frequency control signal generating means including a passive resonant frequency determining element; means for applying said first signal to said passive resonant frequency determining element; and, output means coupled to said passive resonant frequency determining element for deriving an oscillator output signal therefrom.
Claim 12
Dependent Claim
206 words
Apparatus for controlling the frequency of a periodic signal comprising: means for generating a first signal controllable in frequency about a predetermined center frequency, said first signal having a noise power density below a predetermined level at Fourier frequencies above a first Fourier frequency; means for generating a second signal having a frequency approximately equal to said center frequency and having a noise power density below said predetermined level at Fourier frequencies below a second Fourier frequency higher than the first Fourier frequency; means for comparing the first and second signals in phase and for generating a phase control signal responsively to the phase comparison between the first and second signals; means for generating a frequency control signal responsively to the first signal; means for modifying the frequency control signal in response to the phase control signal at Fourier frequencies below the second Fourier frequency; means for controlling the frequency of the first signal in response to the modified frequency control signal; said frequency control signal generating means including a passive resonant frequency determining element; means for applying said first signal to said passive resonant frequency determining element; and, output means coupled to said passive resonant frequency determining element for deriving an oscillator output signal therefrom.
Claim 13
Dependent Claim
68 words
The apparatus of claim 7 wherein the frequency control signal generating means additionally includes: means for shifting the phase of a portion of the first signal by a fixed amount to provide a phase shifted first signal; and, means for comparing the phase of an output of said passive resonant frequency determining element to the phase of the phase shifted first signal to generate the frequency control signal.
Claim 14
Dependent Claim
283 words
Apparatus for controlling the frequency of a periodic signal comprising: means for generating a first signal controllable in frequency about a predetermined center frequency, said first signal having a noise power density below a predetermined level at Fourier frequencies above a first Fourier frequency; means for generating a second signal having a frequency approximately equal to said center frequency and having a noise power density below said predetermined level at Fourier frequencies below a second Fourier frequency higher than the first Fourier frequency; means for comparing the first and second signals in phase and for generating a phase control signal responsively to the phase comparison between the first and second signals; means for generating a frequency control signal responsively to the first signal; means for modifying the frequency control signal in response to the phase control signal at Fourier frequencies below the second Fourier frequency; means for controlling the frequency of the first signal in response to the modified frequency control signal; and wherein the frequency control signal generating means comprises: a resonant, frequency determining element; means for applying the first signal to the resonant, frequency determining element to gEnerate a frequency reference signal; means for shifting the phase of a portion of the first signal by a fixed amount to provide a phase shifted first signal; means for comparing the phase of the frequency reference signal to the phase of the phase shifted first signal to generate the frequency control signal; and, wherein said means for modifying the frequency control signal in response to the phase control signal comprises means for shifting the phase of the phase shifted first signal by an amount related to the magnitude of the phase control signal.
Claim 15
Dependent Claim
283 words
Apparatus for controlling the frequency of a periodic signal comprising: means for generating a first signal controllable in frequency about a predetermined center frequency, said first signal having a noise power density below a predetermined level at Fourier frequencies above a first Fourier frequency; means for generating a second signal having a frequency approximately equal to said center frequency and having a noise power density below said predetermined level at Fourier frequencies below a second Fourier frequency higher than the first Fourier frequency; means for comparing the first and second signals in phase and for generating a phase control signal responsively to the phase comparison between the first and second signals; means for generating a frequency control signal responsively to the first signal; means for modifying the frequency control signal in response to the phase control signal at Fourier frequencies below the second Fourier frequency; means for controlling the frequency of the first signal in response to the modified frequency control signal; and wherein the frequency control signal generating means comprises: a resonant, frequency determining element; means for applying the first signal to the resonant, frequency determining element to gEnerate a frequency reference signal; means for shifting the phase of a portion of the first signal by a fixed amount to provide a phase shifted first signal; means for comparing the phase of the frequency reference signal to the phase of the phase shifted first signal to generate the frequency control signal; and, wherein said means for modifying the frequency control signal in response to the phase control signal comprises means for shifting the phase of the phase shifted first signal by an amount related to the magnitude of the phase control signal.
Claim 16
Dependent Claim
309 words
Apparatus for controlling the frequency of a periodic signal comprising: means for generating a first signal controllable in frequency about a predetermined center frequency, said first signal having a noise power density below a predetermined level at Fourier frequencies above a first Fourier frequency; means for generating a second signal having a frequency approximately equal to said center frequency and having a noise power density below said predetermined level at Fourier frequencies below a second Fourier frequency higher than the first Fourier frequency; means for comparing the first and second signals in phase and for generating a phase control signal responsively to the phase comparison between the first and second signals; means for generating a frequency control signal responsively to the first signal; means for modifying the frequency control signal in response to the phase control signal at Fourier frequencies below the second Fourier frequency; means for controlling the frequency of the first signal in response to the modified frequency control signal; and wherein the frequency control signal generating means comprises: a resonant, frequency determining element; means for applying the first signal to the resonant, frequency determining element to generate a frequency reference signal; means for shifting the phase of a portion of the first signal by a fixed amount to provide a phase shifted first signal; means for comparing the phase of the frequency reference signal to the phase of the phase shifted first signal to generate the frequency control signal; and additionally including means for filtering the phase control signal to remove all components having frequencies above a predetermined frequency lower than the second Fourier frequency; and; wherein said means for modifying the frequency control signal in response to the phase control signal comprises means for shifting the phase of the phase shifted first signal by an amount related to the magnitude of the phase control signal.
Claim 17
Dependent Claim
309 words
Apparatus for controlling the frequency of a periodic signal comprising: means for generating a first signal controllable in frequency about a predetermined center frequency, said first signal having a noise power density below a predetermined level at Fourier frequencies above a first Fourier frequency; means for generating a second signal having a frequency approximately equal to said center frequency and having a noise power density below said predetermined level at Fourier frequencies below a second Fourier frequency higher than the first Fourier frequency; means for comparing the first and second signals in phase and for generating a phase control signal responsively to the phase comparison between the first and second signals; means for generating a frequency control signal responsively to the first signal; means for modifying the frequency control signal in response to the phase control signal at Fourier frequencies below the second Fourier frequency; means for controlling the frequency of the first signal in response to the modified frequency control signal; and wherein the frequency control signal generating means comprises: a resonant, frequency determining element; means for applying the first signal to the resonant, frequency determining element to generate a frequency reference signal; means for shifting the phase of a portion of the first signal by a fixed amount to provide a phase shifted first signal; means for comparing the phase of the frequency reference signal to the phase of the phase shifted first signal to generate the frequency control signal; and additionally including means for filtering the phase control signal to remove all components having frequencies above a predetermined frequency lower than the second Fourier frequency; and; wherein said means for modifying the frequency control signal in response to the phase control signal comprises means for shifting the phase of the phase shifted first signal by an amount related to the magnitude of the phase control signal.
Claim 18
Dependent Claim
162 words
Apparatus for controlling the frequency of an output signal from a voltage controlled oscillator with a high degree of stability comprising: a crystal controlled oscillator providing an output signal; means for generating a phase control signal related in amplitude to the phase relationship between the voltage controlled oscillator output signal and the crystal controlled oscillator output signal; means for shifting the phase of a portion of the voltage controlled oscillator output signal by a predetermined fixed amount modified by a variable amount related to the amplitude of the phase control signal; a frequency determining element excited by the voltage controlled oscillator output signal; means for generating a frequency control signal related in amplitude to the phase relationship between the phase shifted voltage controlled oscillator output signal and an output signal from the frequency determining element excited by the voltage controlled oscillator output signal; and, means for controlling the frequency of the voltage controlled oscillator output signal responsively to the frequency control signal.
Claim 19
Dependent Claim
162 words
Apparatus for controlling the frequency of an output signal from a voltage controlled oscillator with a high degree of stability comprising: a crystal controlled oscillator providing an output signal; means for generating a phase control signal related in amplitude to the phase relationship between the voltage controlled oscillator output signal and the crystal controlled oscillator output signal; means for shifting the phase of a portion of the voltage controlled oscillator output signal by a predetermined fixed amount modified by a variable amount related to the amplitude of the phase control signal; a frequency determining element excited by the voltage controlled oscillator output signal; means for generating a frequency control signal related in amplitude to the phase relationship between the phase shifted voltage controlled oscillator output signal and an output signal from the frequency determining element excited by the voltage controlled oscillator output signal; and, means for controlling the frequency of the voltage controlled oscillator output signal responsively to the frequency control signal.
Claim 20
Dependent Claim
24 words
The apparatus of claim 11 including means for filtering the phase control signal to remove components having a frequency above a predetermined Fourier frequency.
Claim 21
Dependent Claim
219 words
Apparatus For generating a low noise, high frequency output signal comprising: a crystal controlled signal source operable to generate a first signal at a first predetermined frequency; a voltage controlled signal source operable to generate a second signal over a range of frequencies including said first predetermined frequency in response to a frequency control signal; means for comparing said first and second signals in phase and for generating a phase control signal in response to the phase comparison between said first and second signals; means for filtering said phase control signal to remove all frequency components above a second predetermined frequency; an automatic frequency control loop for generating said frequency control signal, said control loop including a frequency determining element for generating a frequency reference signal in response to said second signal, a signal controllable phase shifter responsive to said second signal for providing a phase shifted second signal and means for comparing said reference signal and said phase shifted second signal in phase to thereby generate said frequency control signal; circuit means for applying said filtered phase control signal to said signal controllable phase shifter to thereby modify said frequency control signal at frequencies below said second predetermined frequency; and, means for providing an output signal responsively to said frequency determining element in said automatic frequency control loop.
Claim 22
Dependent Claim
219 words
Apparatus For generating a low noise, high frequency output signal comprising: a crystal controlled signal source operable to generate a first signal at a first predetermined frequency; a voltage controlled signal source operable to generate a second signal over a range of frequencies including said first predetermined frequency in response to a frequency control signal; means for comparing said first and second signals in phase and for generating a phase control signal in response to the phase comparison between said first and second signals; means for filtering said phase control signal to remove all frequency components above a second predetermined frequency; an automatic frequency control loop for generating said frequency control signal, said control loop including a frequency determining element for generating a frequency reference signal in response to said second signal, a signal controllable phase shifter responsive to said second signal for providing a phase shifted second signal and means for comparing said reference signal and said phase shifted second signal in phase to thereby generate said frequency control signal; circuit means for applying said filtered phase control signal to said signal controllable phase shifter to thereby modify said frequency control signal at frequencies below said second predetermined frequency; and, means for providing an output signal responsively to said frequency determining element in said automatic frequency control loop.
References Cited (Backward Citations)
US3593181A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |