US3719946A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Radar phase comparison system including a superhetrodyne receiver
Assignee: United States Department of the Air Force
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Filing: 1969-01-27
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Granted: 1973-03-06
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Expires: 1989-01-27
Abstract
Abstract A radar system of object recognition wherein multiple coherent harmonic frequency signals are directed towards an object and the return signals therefrom are passed through a superhetrodyne receiver for phase comparison purposes to provide a resultant signal having characteristics distinguishing the object from its background.
Inventors
- 👤 C Sletten
- 👤 W Goggins
- 👤 P Blacksmith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:50
CPC Classifications
G; G01; G01S; G01S7/00; G01S7/02; G01S7/41; G01S7/414
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
345 words
A radar system including a superhetrodyne receiver for recognizing signal scattering targets such as aircraft and tanks by the characteristic phase shifts of the scattered return signals therefrom comprising first stable means to generate a first signal of preselected frequency, said preselected frequency being directly related to the size of said signal scattering targets, first means to multiply the frequency of said first signal by a preselected constant n to provide a second signal coherently, harmonically related to said first signal, means to separately amplify said first and second signals to provide high power thereto, means to modulate said amplifying means to provide pulse outputs therefrom, means to transmit said first and second pulse high power signals toward said signal scattering targets, second stable means to generate a third signal of preselected intermediate frequency differing in frequency from said first and second signals, meAns to mix said first signal with said third signal to provide a predetermined first difference signal, second means to multiply said third signal by said preselected constant n to provide a fourth signal, second means to mix said second signal and said fourth signal to provide a predetermined second difference signal, antenna means to receive said scattered signals from said signal scattering targets, first receiver means to amplify said received signals, said first receiver means being tuned to the frequency of said first signal, second receiver means to amplify said received signals, said second receiver means being tuned to the frequency of said second signal, third mixer means receiving simultaneously the output from said first receiver means and said first difference signal, fourth mixer means receiving simultaneously the output from said second receiver and said second difference signal, first and second intermediate amplifiers passing the outputs from said third and fourth mixers, respectively, third means to multiply the output from said first intermediate amplifier by said constant n, and means to phase compare the output signal from said third multiplying means to the output signal from said second intermediate amplifier to provide a resultant signal representative of said signal scattering targets.
Claim 2
Dependent Claim
345 words
A radar system including a superhetrodyne receiver for recognizing signal scattering targets such as aircraft and tanks by the characteristic phase shifts of the scattered return signals therefrom comprising first stable means to generate a first signal of preselected frequency, said preselected frequency being directly related to the size of said signal scattering targets, first means to multiply the frequency of said first signal by a preselected constant n to provide a second signal coherently, harmonically related to said first signal, means to separately amplify said first and second signals to provide high power thereto, means to modulate said amplifying means to provide pulse outputs therefrom, means to transmit said first and second pulse high power signals toward said signal scattering targets, second stable means to generate a third signal of preselected intermediate frequency differing in frequency from said first and second signals, meAns to mix said first signal with said third signal to provide a predetermined first difference signal, second means to multiply said third signal by said preselected constant n to provide a fourth signal, second means to mix said second signal and said fourth signal to provide a predetermined second difference signal, antenna means to receive said scattered signals from said signal scattering targets, first receiver means to amplify said received signals, said first receiver means being tuned to the frequency of said first signal, second receiver means to amplify said received signals, said second receiver means being tuned to the frequency of said second signal, third mixer means receiving simultaneously the output from said first receiver means and said first difference signal, fourth mixer means receiving simultaneously the output from said second receiver and said second difference signal, first and second intermediate amplifiers passing the outputs from said third and fourth mixers, respectively, third means to multiply the output from said first intermediate amplifier by said constant n, and means to phase compare the output signal from said third multiplying means to the output signal from said second intermediate amplifier to provide a resultant signal representative of said signal scattering targets.
Claim 3
Dependent Claim
345 words
A radar system including a superhetrodyne receiver for recognizing signal scattering targets such as aircraft and tanks by the characteristic phase shifts of the scattered return signals therefrom comprising first stable means to generate a first signal of preselected frequency, said preselected frequency being directly related to the size of said signal scattering targets, first means to multiply the frequency of said first signal by a preselected constant n to provide a second signal coherently, harmonically related to said first signal, means to separately amplify said first and second signals to provide high power thereto, means to modulate said amplifying means to provide pulse outputs therefrom, means to transmit said first and second pulse high power signals toward said signal scattering targets, second stable means to generate a third signal of preselected intermediate frequency differing in frequency from said first and second signals, meAns to mix said first signal with said third signal to provide a predetermined first difference signal, second means to multiply said third signal by said preselected constant n to provide a fourth signal, second means to mix said second signal and said fourth signal to provide a predetermined second difference signal, antenna means to receive said scattered signals from said signal scattering targets, first receiver means to amplify said received signals, said first receiver means being tuned to the frequency of said first signal, second receiver means to amplify said received signals, said second receiver means being tuned to the frequency of said second signal, third mixer means receiving simultaneously the output from said first receiver means and said first difference signal, fourth mixer means receiving simultaneously the output from said second receiver and said second difference signal, first and second intermediate amplifiers passing the outputs from said third and fourth mixers, respectively, third means to multiply the output from said first intermediate amplifier by said constant n, and means to phase compare the output signal from said third multiplying means to the output signal from said second intermediate amplifier to provide a resultant signal representative of said signal scattering targets.
Claim 4
Dependent Claim
345 words
A radar system including a superhetrodyne receiver for recognizing signal scattering targets such as aircraft and tanks by the characteristic phase shifts of the scattered return signals therefrom comprising first stable means to generate a first signal of preselected frequency, said preselected frequency being directly related to the size of said signal scattering targets, first means to multiply the frequency of said first signal by a preselected constant n to provide a second signal coherently, harmonically related to said first signal, means to separately amplify said first and second signals to provide high power thereto, means to modulate said amplifying means to provide pulse outputs therefrom, means to transmit said first and second pulse high power signals toward said signal scattering targets, second stable means to generate a third signal of preselected intermediate frequency differing in frequency from said first and second signals, meAns to mix said first signal with said third signal to provide a predetermined first difference signal, second means to multiply said third signal by said preselected constant n to provide a fourth signal, second means to mix said second signal and said fourth signal to provide a predetermined second difference signal, antenna means to receive said scattered signals from said signal scattering targets, first receiver means to amplify said received signals, said first receiver means being tuned to the frequency of said first signal, second receiver means to amplify said received signals, said second receiver means being tuned to the frequency of said second signal, third mixer means receiving simultaneously the output from said first receiver means and said first difference signal, fourth mixer means receiving simultaneously the output from said second receiver and said second difference signal, first and second intermediate amplifiers passing the outputs from said third and fourth mixers, respectively, third means to multiply the output from said first intermediate amplifier by said constant n, and means to phase compare the output signal from said third multiplying means to the output signal from said second intermediate amplifier to provide a resultant signal representative of said signal scattering targets.
Claim 5
Dependent Claim
17 words
A radar system as described in claim 1 further including means to visually display said resultant signal.
References Cited (Backward Citations)
US3397398A
Cited
US3374478A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-05 | 1976-09-04 | 1977-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-05 | 1980-09-04 | 1981-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-05 | 1984-09-04 | 1985-03-06 | $7700.00 | Window Closed / Lapsed |