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US3943510A
Expired / Lapsed
US
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Pulse-repetition frequency discriminator (PRFD) for tracking radar signals
Assignee: United States Department of the Navy
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Filing: 1964-10-02
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Granted: 1976-03-09
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Expires: 1984-10-02
Abstract
Abstract 1. In a pulse-repetition frequency discriminator, the combination compris: g A. a pulse generator for generating pulses at a predetermined reference frequency, B. a gate generator coupled to said pulse generator and being responsive to the generated pulses to generate a gate signal having a width of a predetermined percentage of the repetition period of the predetermined reference frequency, C. ramp generator means coupled to said gate generator for converting said gate signal into a triangular shaped signal, D. a normally closed gate circuit coupled to said ramp generator means and to an input terminal adapted to receive radar pulses of interest and being responsive to received radar pulses having a frequency within said gate signal to pass a portion of said triangular shaped signal, E. circuit means having an input coupled to said normally closed gate circuit and having a reference voltage equal to one-half the amplitude voltage of said triangular shaped signal and having an output coupled to said pulse generator for feeding a corrective voltage proportional to the difference between the amplitude of the output voltage passed by said normally closed gate and said reference voltage to said pulse generator to change the PRF of said pulse generator in a direction to reduce said corrective voltage to zero.
Inventors
- 👤 Criley Orton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:04
CPC Classifications
G; G01; G01S; G01S13/00; G01S13/66; G01S13/70
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
209 words
In a pulse-repetition frequency discriminator, the combination comprising: a. a pulse generator for generating pulses at a predetermined reference frequency, b. a gate generator coupled to said pulse generator and being responsive to the generated pulses to generate a gate signal having a width of a predetermined percentage of the repetition period of the predetermined reference frequency, c. ramp generator means coupled to said gate generator for converting said gate signal into a triangular shaped signal, d. a normally closed gate circuit coupled to said ramp generator means and to an input terminal adapted to receive radar pulses of interest and being responsive to received radar pulses having a frequency within said gate signal to pass a portion of said triangular shaped signal, e. circuit means having an input coupled to said normally closed gate circuit and having a reference voltage equal to one-half the amplitude voltage of said triangular shaped signal and having an output coupled to said pulse generator for feeding a corrective voltage proportional to the difference between the amplitude of the output voltage passed by said normally closed gate and said reference voltage to said pulse generator to change the PRF of said pulse generator in a direction to reduce said corrective voltage to zero.
Claim 2
Dependent Claim
209 words
In a pulse-repetition frequency discriminator, the combination comprising: a. a pulse generator for generating pulses at a predetermined reference frequency, b. a gate generator coupled to said pulse generator and being responsive to the generated pulses to generate a gate signal having a width of a predetermined percentage of the repetition period of the predetermined reference frequency, c. ramp generator means coupled to said gate generator for converting said gate signal into a triangular shaped signal, d. a normally closed gate circuit coupled to said ramp generator means and to an input terminal adapted to receive radar pulses of interest and being responsive to received radar pulses having a frequency within said gate signal to pass a portion of said triangular shaped signal, e. circuit means having an input coupled to said normally closed gate circuit and having a reference voltage equal to one-half the amplitude voltage of said triangular shaped signal and having an output coupled to said pulse generator for feeding a corrective voltage proportional to the difference between the amplitude of the output voltage passed by said normally closed gate and said reference voltage to said pulse generator to change the PRF of said pulse generator in a direction to reduce said corrective voltage to zero.
Claim 3
Dependent Claim
92 words
The discriminator of claim 1 wherein said pulse generator comprises: a. a triangle generator for generating triangle wave shaped voltages, b. a multiar circuit coupled to said triangle generator for generating an output pulse when the amplitude of the triangle voltage reaches a predetermined value, c. discharge generator means coupled to said triangle generator and to said multiar circuit and being responsive to the output pulse of said multiar circuit for generating a discharge pulse to terminate the output voltage from said triangle generator and cause a new waveform signal to start.
Claim 4
Dependent Claim
86 words
The discriminator of claim 2 wherein said multiar circuit comprises: a. a transistor having a collector base and emitter, b. input circuit means including a feedback transformer, diode and coupling capacitor connected in series, said coupling capacitor being connected to said base, c. a reference voltage connected to a point intermediate said diode and said capacitor, said diode being poled so that an input signal having a magnitude less than said reference voltage is blocked, d. circuit means coupling a positive feedback to said feedback transformer.
Claim 5
Dependent Claim
62 words
The discriminator of claim 1 wherein said normally closed gate circuit comprises: a. a ring type diode bridge, b. a Zener diode, c. an input transformer having a primary winding and a secondary winding connected in series with said Zener diode between the first and third bridge junctions, d. said triangular shaped signal being connected between the second and fourth bridge junctions.
Claim 6
Dependent Claim
50 words
The discriminator of claim 1 wherein said circuit means comprises: a. a storage capacitor coupled to said gate circuit and to said reference voltage so that when the output from said gate circuit is different from said reference voltage a charge proportional to the difference will flow in said capacitor.
References Cited (Backward Citations)
US3013260A
Cited
US3758856A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-09 | 1979-09-08 | 1980-03-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-09 | 1983-09-08 | 1984-03-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-09 | 1987-09-08 | 1988-03-09 | $7700.00 | Window Closed / Lapsed |