US3729688A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oscillator with switchable filter control voltage input for rapidly switching to discrete frequency outputs
Assignee: Motorola Solutions Inc
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Filing: 1971-12-15
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Granted: 1973-04-24
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Expires: 1991-12-15
Abstract
Abstract A voltage controlled oscillator controllable to discrete frequency outputs, which outputs are applied to a phase detector through divider circuits and compared to a reference signal of the same frequency, is controlled to discrete frequency outputs by variable voltages or variable width pulses, proportional to the difference in phase between the two signals, from the phase detector which pulses are applied to the oscillator through loop filters. Each loop filter is an RC circuit which integrates the pulses and serves as a memory to retain a relatively constant voltage thereacross. Therefore, when a specific loop filter is switched into the circuit the voltage controlled oscillator is rapidly switched to a discrete frequency output proportional to the voltage stored in the loop filter.
Inventors
- 👤 F Cerny
- 👤 D Linder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:15
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/16; H03L7/18; H03L7/183; H03L7/187; H03L7/08; H03L7/085; H03L7/093; H03L7/10; H03L7/107; H03L7/1075
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
93 words
Apparatus rapidly controllable to discrete frequency outputs comprising: a. voltage controlled oscillator means having an input adapted to have a voltage applied thereto and an output providing a signal dependent upon the amplitude of voltage applied to the input; b. a plurality of voltage storage means each including a filter having a relatively small bandwidth and each adapted to have a different voltage thereacross for controlling said oscillator means to a discrete frequency; and c. switching means for selectively connecting one of said voltage storage means to the input of said oscillator means.
Claim 2
Dependent Claim
93 words
Apparatus rapidly controllable to discrete frequency outputs comprising: a. voltage controlled oscillator means having an input adapted to have a voltage applied thereto and an output providing a signal dependent upon the amplitude of voltage applied to the input; b. a plurality of voltage storage means each including a filter having a relatively small bandwidth and each adapted to have a different voltage thereacross for controlling said oscillator means to a discrete frequency; and c. switching means for selectively connecting one of said voltage storage means to the input of said oscillator means.
Claim 3
Dependent Claim
21 words
Apparatus as set forth in claim 1 wherein the switching means includes a field effect transistor for each voltage storage means.
Claim 4
Dependent Claim
158 words
Apparatus rapidly controllable to discrete frequency outputs comprising: a. voltage controlled oscillator means having an input adapted to have a voltage applied thereto and an output providing a signal dependent upon the amplitude of voltage applied to the input; b. a plurality of voltage storage means each adapted to have a different voltage thereacross for controlling said oscillator means to a discrete frequency; c. switching means for selectively connecting one of said voltage storage means to the input of said oscillator means; and d. comparing means having an output connected to said voltage storage means and a plurality of inputs, said comparing means providing a signal at said output dependent upon the relationship of predetermined characteristics of signals applied to said inputs, reference means connected to one of said inputs of said comparing means for supplying a reference signal thereto, and means coupling the output of said oscillator means to one of said inputs of said comparing means.
Claim 5
Dependent Claim
158 words
Apparatus rapidly controllable to discrete frequency outputs comprising: a. voltage controlled oscillator means having an input adapted to have a voltage applied thereto and an output providing a signal dependent upon the amplitude of voltage applied to the input; b. a plurality of voltage storage means each adapted to have a different voltage thereacross for controlling said oscillator means to a discrete frequency; c. switching means for selectively connecting one of said voltage storage means to the input of said oscillator means; and d. comparing means having an output connected to said voltage storage means and a plurality of inputs, said comparing means providing a signal at said output dependent upon the relationship of predetermined characteristics of signals applied to said inputs, reference means connected to one of said inputs of said comparing means for supplying a reference signal thereto, and means coupling the output of said oscillator means to one of said inputs of said comparing means.
Claim 6
Dependent Claim
16 words
Apparatus as set forth in claim 9 wherein the reference means includes a crystal controlled oscillator.
Claim 7
Dependent Claim
37 words
Apparatus as set forth in claim 4 wherein the coupling means includes circuitry connected to said switching means and programmed to provide a signal at the comparing means having approximately the same frequency as the reference means.
Claim 8
Dependent Claim
55 words
Apparatus as set forth in claim 5 wherein the comparing means includes a phase detector for supplying pulses to the voltage storage means which pulses have a width proportional to the phase error between the frequency of the output signal from the reference means and the frequency of the output signal from the coupling means.
Claim 9
Dependent Claim
37 words
Apparatus as set forth in claim 6 wherein the reference means is connected to the switching means for controlling the switching means to operate only at predetermined times relative to the output signal from the reference means.
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) | 1976-04-23 | 1976-10-23 | 1977-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-23 | 1980-10-23 | 1981-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-23 | 1984-10-23 | 1985-04-24 | $7700.00 | Window Closed / Lapsed |