Patent US3699448A successfully refreshed from Google Patents.
US3699448A
Expired / Lapsed
US
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Precision generation of linear f. m. signal
Assignee: Lockheed Martin Tactical Systems Inc
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Filing: 1971-02-08
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Granted: 1972-10-17
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Expires: 1991-02-08
Abstract
Abstract The invention achieves a linear waveform that is swept in frequency with great precision by means of a servo control that uses an error signal derived from the measurement of the actual phase of the swept frequency waveform at equal time intervals. These time intervals are chosen so the phase should be multiples of 2 pi at the sample times. These phase values coincide with zero crossings of the signal. If the signal amplitude is not zero, the sense of the phase errors is detected, and then sweep linearity corrections are applied in a closed loop feedback.
Inventors
- 👤 Gregory L Martin
- 👤 Lloyd R Blair
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:06
CPC Classifications
H; H03; H03B; H03B23/00; H03B2200/00; H03B2200/006; H03B2200/0092
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
177 words
Apparatus to generate and control the linearity of a linear F.M. sweep pulse signal comprising: a. a voltage controlled oscillator driven by a control voltage generator, the voltage controlled oscillator being phase locked, between sweep pulse signals, to a reference freQuency oscillator by means of a phase lock circuit. b. a gate pulse generator providing a train of pulses, the timing of which is determined by the desired sweep characteristics of the F.M. sweep pulse signal, which controls the gating of sample signals from the voltage controlled oscillator; c. a first circuit means for detecting and holding the peak amplitude of the sample signals from the voltage controlled oscillator so as to create sample levels; d. a plurality of gates which, under the control of the gate pulse generator, channel the sample levels of the first circuit means to the respective integrators associated with each gate; and e. a summing amplifier which combines the outputs of the integrators with the output of the control voltage generator so as to modify the input to the voltage controlled oscillator.
Claim 2
Dependent Claim
177 words
Apparatus to generate and control the linearity of a linear F.M. sweep pulse signal comprising: a. a voltage controlled oscillator driven by a control voltage generator, the voltage controlled oscillator being phase locked, between sweep pulse signals, to a reference freQuency oscillator by means of a phase lock circuit. b. a gate pulse generator providing a train of pulses, the timing of which is determined by the desired sweep characteristics of the F.M. sweep pulse signal, which controls the gating of sample signals from the voltage controlled oscillator; c. a first circuit means for detecting and holding the peak amplitude of the sample signals from the voltage controlled oscillator so as to create sample levels; d. a plurality of gates which, under the control of the gate pulse generator, channel the sample levels of the first circuit means to the respective integrators associated with each gate; and e. a summing amplifier which combines the outputs of the integrators with the output of the control voltage generator so as to modify the input to the voltage controlled oscillator.
Claim 3
Dependent Claim
41 words
The apparatus according to claim 1 wherein the plurality of gates which, under the control of the gate pulse generator, channels the sample levels of the first circuit means to the respective integrators associated with each gate comprises an electronic commutator.
Claim 4
Dependent Claim
57 words
The apparatus according to claim 1 wherein a reference frequency oscillator comprises a STALO and wherein a trigger pulse means coordinated with the STALO and the gate pulse generator is provided to insure time coordination between the initiation of the F.M. sweep pulse signal from the voltage controlled oscillator and the gating of the gate pulse generator.
Claim 5
Dependent Claim
44 words
Apparatus according to claim 1 which includes means to short out all the integrators if any one integrator exceeds a predetermined level and to initiate the sampling of the output of the voltage controlled oscillator again by proper coordination with the gate pulse generator.
Claim 6
Dependent Claim
31 words
The apparatus according to claim 1 wherein the gate pulse generator generates a gate width of the order of one half of the period of the highest frequency being sampled thereby.
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) | 1975-10-17 | 1976-04-17 | 1976-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-17 | 1980-04-17 | 1980-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-17 | 1984-04-17 | 1984-10-17 | $7700.00 | Window Closed / Lapsed |