US3840822A
Expired / Lapsed
US
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Decadically adjustable frequency synthesizer
Assignee: Wandel and Golterman GmbH and Co
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Filing: 1973-08-16
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Granted: 1974-10-08
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Expires: 1993-08-16
Abstract
Abstract A variable-frequency oscillator works through a pulse shaper, a pulse-rate modifier and a frequency divider of step-down ratio n: 1 into a phase comparator also receiving the output of a generator of reference frequency f. To adjust the operating frequency F of the oscillator at a selected value F nf + OR k, a pulse train of repetition frequency or cadence k is fed to the pulse-rate modifier to reduce or augment the number of pulses per second reaching the divider. The modifying pulse train may be derived from one or more stages of the frequency divider, from a step-down network driving the reference-frequency generator, an independent pulse source.
Inventors
- 👤 G Hoffmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:36
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/16; H03L7/18; H03L7/197; H03L7/1974; H03L7/183; H03L7/185
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
172 words
A frequency synthesizer comprising: oscillator means generating a sequence of spikes of variable repetition frequency F; a generator of reference frequency f < F; a source of control pulses recurring with a cadence k < F; a frequency divider of step-down ratio n : 1 connected to receive said sequence of spikes from said oscillator means; a pulse-rate modifier inserted between said oscillator means and said frequency divider, said modifier having a control input connected to said source for varying the rate of occurrence of said spikes by a unit change of m spikes per control pulse whereby said spikes are delivered to said frequency divider with a mean repetition frequency F'' F + OR - mk; and phase-comparison means connected to receive said reference frequency f from said generator and a mean output frequency F''/n from said frequency divider, said oscillator means being provided with frequency-control means connected to an output of said phase-comparison means for stabilizing said mean output frequency F''/n at a value equal to said reference frequency f.
Claim 2
Dependent Claim
172 words
A frequency synthesizer comprising: oscillator means generating a sequence of spikes of variable repetition frequency F; a generator of reference frequency f < F; a source of control pulses recurring with a cadence k < F; a frequency divider of step-down ratio n : 1 connected to receive said sequence of spikes from said oscillator means; a pulse-rate modifier inserted between said oscillator means and said frequency divider, said modifier having a control input connected to said source for varying the rate of occurrence of said spikes by a unit change of m spikes per control pulse whereby said spikes are delivered to said frequency divider with a mean repetition frequency F'' F + OR - mk; and phase-comparison means connected to receive said reference frequency f from said generator and a mean output frequency F''/n from said frequency divider, said oscillator means being provided with frequency-control means connected to an output of said phase-comparison means for stabilizing said mean output frequency F''/n at a value equal to said reference frequency f.
Claim 3
Dependent Claim
10 words
A frequency synthesizer as defined in claim 1 wherein m
Claim 4
Dependent Claim
37 words
A frequency synthesizer as defined in claim 1 wherein said modifier comprises bistable pulse-storing means connected to be set by a pulse on said control input and to be reset by a Spike from said oscillator means.
Claim 5
Dependent Claim
44 words
A frequency synthesizer as defined in claim 3 wherein said modifier further comprises coincidence means connected to said pulse-storing means and to the output of said oscillator eans for suppressing a spike arriving during an oscillator cycle in which a control pulse is received.
Claim 6
Dependent Claim
22 words
A frequency synthesizer as defined in claim 1, further comprising low-pass filter means inserted between said phase-comparison means and said frequency-control means.
Claim 7
Dependent Claim
50 words
A frequency synthesizer as defined in claim 5 wherein said low-pass filter means comprises an RC network with a capacitive shunt arm and a resistive series arm, said series arm including threshold means for reducing the time constant of said network in response to a predetermined minimum voltage difference thereacross.
Claim 8
Dependent Claim
53 words
A frequency synthesizer as defined in claim 1 wherein said phase-comparison means has input connections to a first branch including said frequency divider and to a second branch including said generator, at least one of said branches including a decadic step-down stage, said source comprising digital selector means connected to said step-down stage.
Claim 9
Dependent Claim
41 words
A frequency synthesizer as defined in claim 7 wherein said source comprises at least one additional decadic step-down stage in cascade with the first-mentioned step-down stage, said selector means comprising individual selectors connected to respective output leads of said step-down stages.
Claim 10
Dependent Claim
46 words
A frequency synthesizer as defined in claim 7 wherein said source comprises a chain of additional decadic step-down stages, said selector means including a plurality of individual selectors connected in parallel to output leads of the first-mentioned step-down stage for respectively controlling said additional step-down stages.
Claim 11
Dependent Claim
28 words
A frequency synthesizer as defined in claim 9, further comprising anti-coincidence circuits inserted in said chain for preventing merger between pulses from associated selectors and from preceding stages.
Claim 12
Dependent Claim
67 words
A frequency synthesizer as defined in claim 9 wherein at least the lowest-ranking stage in said chain generates stepping pulses recurring at a rate lower than said reference frequency, further comprising a digital/analog converter connected to receive the count of said lowest-ranking stage and to derive therefrom an electrical quantity delivered to said phase-comparison means for compensating discontinuities in the output thereof fed to said frequency-control means.
Claim 13
Dependent Claim
36 words
A frequency synthesizer as defined in claim 11, further comprising frequency-discriminating means connected to said oscillator means for delivering to said converter a corrective electrical quantity of a magnitude inversely proportional to said repetition frequency F.
Claim 14
Dependent Claim
18 words
A frequency synthesizer as defined in claim 7 wherein said step-down stage forms part of said frequency divider.
Claim 15
Dependent Claim
17 words
A frequency synthesizer as defined in claim 7 wherein said step-down stage forms part of said generator.
Claim 16
Dependent Claim
59 words
A frequency synthesizer as defined in claim 7 wherein said frequency divider includes a plurality of cascaded decadic stages, further comprising at least one supplemental pulse-rate modifier inserted between two of said decadic stages, said selector means including a plurality of individual selectors connected in parallel to output leads of said step-down stage for respectively controlling said pulse-rate modifiers.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-07 | 1978-04-08 | 1978-10-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-07 | 1982-04-08 | 1982-10-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-07 | 1986-04-08 | 1986-10-08 | $7700.00 | Window Closed / Lapsed |