Patent US3852744A successfully refreshed from Google Patents.
US3852744A
Expired / Lapsed
US
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Single time shared receiver and frequency tracker for a beam-lobed doppler radar system
Assignee: Singer Co
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Filing: 1973-01-05
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Granted: 1974-12-03
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Expires: 1993-01-05
Abstract
Abstract A single time shared receiver and frequency tracker for a beam lobed Doppler radar system. The returns from the fore and aft beams, which are radiated simultaneously are separated through a process of mixing and filtering to obtain two signals which when summed will provide the fore signal and when differenced the aft signal. The sum and difference are alternately sampled and provided to the freqency tracker which includes means to separately store each of the four Doppler system frequencies.
Inventors
- 👤 R Slater
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:46
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/02; G01S13/50; G01S13/58; G01S13/60
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
267 words
In a Doppler navigation system comprising at least a microwave transmitter, and a signal to frequency modulate the transmitter, a transmitting antenna coupled to the transmitter to simultaneously transmit at least a pair of fore and aft beams, a receiving antenna to receive the reflected beam signals containing respective fore and aft doppler return signals, and a receiver front end including means having the received signal as an input to provide from the received beam signal a signal at a lower intermediate frequency, means to separate the first and second doppler return signals obtained comprising: a. an oscillator operating at the intermediate frequency; b. a single sideband modulator having the output of said oscillator and the frequency modulating signal as input and providing a single sideband output; c. a quad network having the output of said modulator as an input and providing first and second outputs at said frequency but shifted in phase 90* from each other; d. a first mixer having the output of the receiver front end and said first quad output as inputs; e. means to shift the output of said first mixer 90*; f. a second mixer having the output of the receiver front end and said second quad outputs as inputs; g. a summing amplifier having as inputs the outputs of said second mixer and said phase shifter; and h. a difference amplifier having as inputs the outputs of said second mixer and said phase shifter whereby the output of said summing amplifier will be the fore doppler return signal and the output of said difference amplifier the aft doppler return signal.
Claim 2
Dependent Claim
267 words
In a Doppler navigation system comprising at least a microwave transmitter, and a signal to frequency modulate the transmitter, a transmitting antenna coupled to the transmitter to simultaneously transmit at least a pair of fore and aft beams, a receiving antenna to receive the reflected beam signals containing respective fore and aft doppler return signals, and a receiver front end including means having the received signal as an input to provide from the received beam signal a signal at a lower intermediate frequency, means to separate the first and second doppler return signals obtained comprising: a. an oscillator operating at the intermediate frequency; b. a single sideband modulator having the output of said oscillator and the frequency modulating signal as input and providing a single sideband output; c. a quad network having the output of said modulator as an input and providing first and second outputs at said frequency but shifted in phase 90* from each other; d. a first mixer having the output of the receiver front end and said first quad output as inputs; e. means to shift the output of said first mixer 90*; f. a second mixer having the output of the receiver front end and said second quad outputs as inputs; g. a summing amplifier having as inputs the outputs of said second mixer and said phase shifter; and h. a difference amplifier having as inputs the outputs of said second mixer and said phase shifter whereby the output of said summing amplifier will be the fore doppler return signal and the output of said difference amplifier the aft doppler return signal.
Claim 3
Dependent Claim
35 words
The invention according to claim 1 and further including first and second leakage elimination filters interposed respectively between said first mixer and said phase shifter and said second mixer and said summing and difference amplifiers.
Claim 4
Dependent Claim
30 words
The Invention according to claim 1 and further including: A. a frequency tracker; B. means to alternately couple the outputs of said summing and difference amplifiers to said frequency tracker.
Claim 5
Dependent Claim
65 words
The invention according to claim 3 where in said frequency tracker includes a single oscillator controlled by an integrator output with the integrator having a plurality of switched capacitors in its feedback path, one being provided for each beam and further including means to switch into the feedback path a capacitor corresponding to the beam whose return signal is being switched to said frequency tracker.
Claim 6
Dependent Claim
91 words
The invention according to claim 4 wherein the transmitter transmits a fore and aft lobed beam on one side and then a fore and aft lobed beam on the other side, right and left switching occurring at a first rate and beam lobing at a rate which is an even multiple thereof and said means to couple, couples the output of said summing amplifier for at least one lobing cycle and the output of said difference amplifier for at least one lobing cycle for each of the right and left cycles.
Claim 7
Dependent Claim
167 words
In a Doppler navigation system comprising at least a microwave transmitter, and a signal to frequency modulate the transmitter, a transmitting antenna coupled to the transmitter to simultaneously transmit at least a pair of fore and aft beams, a receiving antenna to receive the reflected beam signals containing respective fore and aft doppler return signals, and a receiver front end including means to provide from the received beam signal a signal at a lower intermediate frequency, a method of separating the simultaneously received fore and aft doppler return signals comprising: A. developing, from the intermediate frequency, two signals, one in phase with said frequency and one 90* out of phase with said frequency; B. mixing the signal obtained from the received beam signal respectively with said in phase and said out of phase signal to develop first and second outputs; C. adding said first and second outputs to obtain the fore return signal; and D. differencing said first and second outputs to obtain the aft return signal.
Claim 8
Dependent Claim
167 words
In a Doppler navigation system comprising at least a microwave transmitter, and a signal to frequency modulate the transmitter, a transmitting antenna coupled to the transmitter to simultaneously transmit at least a pair of fore and aft beams, a receiving antenna to receive the reflected beam signals containing respective fore and aft doppler return signals, and a receiver front end including means to provide from the received beam signal a signal at a lower intermediate frequency, a method of separating the simultaneously received fore and aft doppler return signals comprising: A. developing, from the intermediate frequency, two signals, one in phase with said frequency and one 90* out of phase with said frequency; B. mixing the signal obtained from the received beam signal respectively with said in phase and said out of phase signal to develop first and second outputs; C. adding said first and second outputs to obtain the fore return signal; and D. differencing said first and second outputs to obtain the aft return signal.
Claim 9
Dependent Claim
22 words
The invention according to claim 6 and further including alternately providing said fore and said aft return signals to a frequency tracker.
Claim 10
Dependent Claim
60 words
The invention according to claim 7 wherein said frequency tracker includes a single oscillator controlled by an integrator output with the integrator having a plurality of switched capacitors in its feedback path, one being provided for each beam and further including coupling the capacitor associated with the one of the fore and aft signals being input into said feedback path.
Claim 11
Dependent Claim
84 words
The invention according to claim 8 wherein the transmitter transmits a fore and aft lobed beam on one side and then a fore and aft lobed beam on the other side, right and left switching occurring at a first rate and beam lobing at a rate which is an even multiple thereof and said fore return signal is coupled for at least one lobing cycle and said aft return signal for at least one lobing cycle for each of the right and left cycles.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |