US3568077A
Expired / Lapsed
US
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Pseudo voltage controlled oscillator
Assignee: Northrop Grumman Corp
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Filing: 1968-09-03
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Granted: 1971-03-02
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Expires: 1988-09-03
Abstract
Abstract For use in a VLG navigation system, such as the Omega Navigation system, a phase tracking loop in a receiver receives incoming signals from transmitting stations. The tracking loop contains four electronically controlled pseudo voltage-controlled oscillators, to eliminate the need for all but one master crystal oscillator, whose outputs provide necessary signals within the receiver. The pseudo oscillator comprises an integrator and a voltage-to-phase converter using an external clock pulse input and suitable control logic. The voltage-to-phase converter comprises a one-shot multivibrator in which the delay time is proportional to the input signal level. Thus, the periods between return times of the one-shot multivibrator to its original state provide a frequency which is controlled by input voltage level. When the phase-shift range exceeds + OR - 90* , the trigger pulse to the one-shot multivibrator is advanced or delayed, and the integrator is reset to zero.
Inventors
- 👤 Yoshiaki Fujimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:06
CPC Classifications
H; H03; H03K; H03K7/00; H03K7/04; G; G01; G01S; G01S1/00; G01S1/02; G01S1/08; G01S1/20; G01S1/30; G06; G06G; G06G7/00; G06G7/12; G06G7/18; G06G7/184; G06G7/186; G06G7/1865; H03C; H03C3/00; H03K4/00; H03K4/06; H03K4/08; H03K4/48; H03K4/50; H03K4/501; H03K5/00; H03K5/01; H03K5/04
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
86 words
In a system requiring a plurality of stable synchronized voltage controlled oscillators, the improvement comprising a single stable master oscillator and a plurality of pseudo voltage-controlled oscillators; each of said pseudo voltage controlled oscillators comprising an integrator fed by the desired control voltage, and a voltage-to-phase converter connected to the output of said integrator; and means for providing a reference trigger signal to each of said phase converters from said master oscillator, whereby said pseudo voltage-controlled oscillators all have the same stability as said master oscillator.
Claim 2
Dependent Claim
86 words
In a system requiring a plurality of stable synchronized voltage controlled oscillators, the improvement comprising a single stable master oscillator and a plurality of pseudo voltage-controlled oscillators; each of said pseudo voltage controlled oscillators comprising an integrator fed by the desired control voltage, and a voltage-to-phase converter connected to the output of said integrator; and means for providing a reference trigger signal to each of said phase converters from said master oscillator, whereby said pseudo voltage-controlled oscillators all have the same stability as said master oscillator.
Claim 3
Dependent Claim
89 words
A voltage-controlled oscillator comprising an integrator, means for connecting a desired control voltage to the input of said integrator, a one-shot multivibrator, an operational amplifier connected between the output of said integrator and the input of said multivibrator, a reference frequency source, means for connecting said reference frequency source to said multivibrator input to trigger said multivibrator, and a feedback circuit from the output of said multivibrator to an input of said amplifier, whereby the delay time of said multivibrator is proportional to the integral of said control voltage.
Claim 4
Dependent Claim
89 words
A voltage-controlled oscillator comprising an integrator, means for connecting a desired control voltage to the input of said integrator, a one-shot multivibrator, an operational amplifier connected between the output of said integrator and the input of said multivibrator, a reference frequency source, means for connecting said reference frequency source to said multivibrator input to trigger said multivibrator, and a feedback circuit from the output of said multivibrator to an input of said amplifier, whereby the delay time of said multivibrator is proportional to the integral of said control voltage.
Claim 5
Dependent Claim
17 words
Apparatus in accordance with claim 2 wherein said feedback circuit comprises a chopper and a low-pass filter.
Claim 6
Dependent Claim
218 words
A voltage-controlled oscillator comprising an integrator, means for connecting a desired control voltage to the input of said integrator, a one-shot multivibrator, means for connecting the output of said integrator to the input of said multivibrator, a reference frequency source, means producing trigger pulses derived from said reference frequency source and means connecting said trigger pulses to said multivibrator input to trigger said multivibrator, wHereby the delay time of said multivibrator is proportional to the integral of said control voltage, a first flip-flop for detecting a positive multivibrator phase shift of a predetermined amount, a second flip-flop for detecting a negative phase shift of said predetermined amount, counter means fed by clock pulses from said reference frequency source, gate means for obtaining said trigger pulses from said counter means, said clock pulses having a frequency which is a predetermined multiple of the trigger pulse frequency, and operative connections from said first and second flip-flops to said counter means to advance or delay the output waveform of said counter means responsive to said detection so as to advance or delay said trigger pulses by one clock pulse, and means for resetting the control voltage level at said multivibrator input substantially simultaneously with the adjustment of said trigger pulses, whereby continuous phase shift relative to said reference frequency is enabled.
Claim 7
Dependent Claim
218 words
A voltage-controlled oscillator comprising an integrator, means for connecting a desired control voltage to the input of said integrator, a one-shot multivibrator, means for connecting the output of said integrator to the input of said multivibrator, a reference frequency source, means producing trigger pulses derived from said reference frequency source and means connecting said trigger pulses to said multivibrator input to trigger said multivibrator, wHereby the delay time of said multivibrator is proportional to the integral of said control voltage, a first flip-flop for detecting a positive multivibrator phase shift of a predetermined amount, a second flip-flop for detecting a negative phase shift of said predetermined amount, counter means fed by clock pulses from said reference frequency source, gate means for obtaining said trigger pulses from said counter means, said clock pulses having a frequency which is a predetermined multiple of the trigger pulse frequency, and operative connections from said first and second flip-flops to said counter means to advance or delay the output waveform of said counter means responsive to said detection so as to advance or delay said trigger pulses by one clock pulse, and means for resetting the control voltage level at said multivibrator input substantially simultaneously with the adjustment of said trigger pulses, whereby continuous phase shift relative to said reference frequency is enabled.
Claim 8
Dependent Claim
55 words
Apparatus in accordance with claim 4 wherein said resetting means comprises a third flip-flop connected to be temporarily triggered by either of said first and second flip-flops, normally open-switching means connected around said integrator, and means responsive to triggering of said third flip-flop for closing said switching means, whereby said integrator is reset to zero.
Claim 9
Dependent Claim
92 words
A voltage controlled oscillator comprising a resettable integrator, a voltage-to-phase converter connected to the output of said integrator, means for supplying a reference frequency signal to said converter, and control logic sensing the output phase of said converter, said logic including first means for advancing or delaying said signal to said converter by one reference frequency pulse before the output of said converter reaches its maximum plus-or-minus phase shift range, respectively, and said logic including second means for resetting said integrator to zero at the same time as said advance or delay.
Claim 10
Dependent Claim
92 words
A voltage controlled oscillator comprising a resettable integrator, a voltage-to-phase converter connected to the output of said integrator, means for supplying a reference frequency signal to said converter, and control logic sensing the output phase of said converter, said logic including first means for advancing or delaying said signal to said converter by one reference frequency pulse before the output of said converter reaches its maximum plus-or-minus phase shift range, respectively, and said logic including second means for resetting said integrator to zero at the same time as said advance or delay.
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) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |