Patent US3810036A successfully refreshed from Google Patents.
US3810036A
Expired / Lapsed
US
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Phase lock loop for locking on highest amplitude signal
Assignee: HP Inc
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Filing: 1972-10-05
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Granted: 1974-05-07
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Expires: 1992-10-05
Abstract
Abstract A broadband, limiting amplifier is used in the IF portion of a harmonic phase lock loop, preceding the IF bandpass filter. The limiting amplifier gives an output signal of a predetermined magnitude having a frequency corresponding to the input signal having the highest level, and a detector connected to the output of the IF bandpass filter inhibits the phase lock loop whenever the signal passing through the bandpass filter is below the predetermined magnitude.
Inventors
- 👤 A Bloedorn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 21:58
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/16; H03L7/20; G; G01; G01R; G01R23/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
205 words
A harmonic phase lock loop comprising: frequency converting means having a first and second input and an output for converting the frequency of an input signal to a different frequency; a limiting amplifier having an input connected to the output of the frequency converting means and an output for producing an output signal of a predetermined amplitude having a fundamental frequency equal to the frequency of the highest amplitude signal from the output of the frequency converting means; a bandpass filter having an input connected to the output of the limiting amplifier and having an output; a reference frequency source having an output; feedback means having a first input connected to the bandpass filter, a second input connected to the reference frequency source and an output connected to the frequency converting means for supplying a feedback signal to the frequency converting means indicative of the difference between the frequency of an output signal from the bandpass filter and the reference frequency; and control means having an input connected to the output of the bandpass filter and an output connected to a third input of the feedback means for inhibiting the feedback signal whenever the output signal from the bandpass filter is below a predetermined amplitude.
Claim 2
Dependent Claim
205 words
A harmonic phase lock loop comprising: frequency converting means having a first and second input and an output for converting the frequency of an input signal to a different frequency; a limiting amplifier having an input connected to the output of the frequency converting means and an output for producing an output signal of a predetermined amplitude having a fundamental frequency equal to the frequency of the highest amplitude signal from the output of the frequency converting means; a bandpass filter having an input connected to the output of the limiting amplifier and having an output; a reference frequency source having an output; feedback means having a first input connected to the bandpass filter, a second input connected to the reference frequency source and an output connected to the frequency converting means for supplying a feedback signal to the frequency converting means indicative of the difference between the frequency of an output signal from the bandpass filter and the reference frequency; and control means having an input connected to the output of the bandpass filter and an output connected to a third input of the feedback means for inhibiting the feedback signal whenever the output signal from the bandpass filter is below a predetermined amplitude.
Claim 3
Dependent Claim
106 words
A harmonic phase lock loop as in claim 1 wherein: the frequency converting means includes a harmonic mixer having a first input connected to receive the input signal and a variable frequency oscillator having an output connected to a second input of the harmonic mixer; and the feedback means includes a phase detector having a first input connected to the output of the reference frequency source and a second input connected to the output of the bandpass filter, and a feedback amplifier having an input connected to receive the output of the phase detector, the feedback amplifier having an output connected to the variable frequency oscillator.
Claim 4
Dependent Claim
93 words
A harmonic phase lock loop as in claim 2 wherein the control means comprises switching means having a control input and connected between the output of the phase detector and the input of the feedback amplifier for interrupting the signal path therebetween in response to a control signal on the control input, and threshold detecting means connected to the output of the bandpass filter and the control input of the switching means for supplying the control signal when the amplitude of the output signal from the bandpass filter falls below a predetermined level.
Claim 5
Dependent Claim
108 words
A harmonic phase lock loop as in claim 3 including a low pass filter connected between the output of the harmonic mixer and the input of the limiting amplifier and wherein the threshold detecting means comprises a phase shifting circuit having an input connected to the output of the bandpass filter, a second phase detector having a first input connected to an output of the phase shifting circuit and a second input connected to the output of the reference oscillator, and a threshold detector having an input connected to an output of the second phase detector and an output connected to the control input of the switching means.
Claim 6
Dependent Claim
27 words
A harmonic phase lock loop as in claim 2 wherein the limiting amplifier has a bandwidth of one-half of the highest frequency of the variable frequency oscillator.
References Cited (Backward Citations)
US3218572A
Cited
GB1125916A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-06 | 1977-11-05 | 1978-05-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-06 | 1981-11-05 | 1982-05-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-06 | 1985-11-05 | 1986-05-07 | $7700.00 | Window Closed / Lapsed |