US3820034A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Digital signal regenerators
Assignee: Post Office
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Filing: 1973-03-09
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Granted: 1974-06-25
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Expires: 1993-03-09
Abstract
Abstract A digital signal regenerator in which a local oscillator is synchronised with an incoming signal by means of a conventional second order phase locked loop, but the regenerated signals are timed by an oscillator controlled by the time integral of the error signals from the phase locked loop without any damping. In the described example a single oscillator is used and the linear damping term is introduced by means of a phase shifter effective on the oscillations from the oscillator to shift their phase by an amount dependent on the time integral of the error signal. In addition to a trigger circuit timing the regenerated digital signals, a second trigger is provided controlled by the phase shifted oscillations as a discriminator for receiving the input digital signals.
Inventors
- 👤 J Ball
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:15
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/081
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
104 words
Apparatus for regenerating digital signals having means for producing first and second oscillations, means for comparing the first oscillation with an input digital signal to produce aN error signal representing the phase difference between the first oscillation and the input digital signal, the frequency of the first oscillation being dependent on the time integral of the error signal the integral incorporating a damping term, and the frequency of the second oscillation being dependent on the time integral of the error signal without a damping term, and means responsive to the second oscillation to form regenerated digital signal in response to the input digital signals.
Claim 2
Dependent Claim
104 words
Apparatus for regenerating digital signals having means for producing first and second oscillations, means for comparing the first oscillation with an input digital signal to produce aN error signal representing the phase difference between the first oscillation and the input digital signal, the frequency of the first oscillation being dependent on the time integral of the error signal the integral incorporating a damping term, and the frequency of the second oscillation being dependent on the time integral of the error signal without a damping term, and means responsive to the second oscillation to form regenerated digital signal in response to the input digital signals.
Claim 3
Dependent Claim
107 words
Apparatus according to claim 1, in which the means for producing first and second oscillations includes a oscillator of controllable frequency, integrating means connected to receive the error signal and to produce a control signal dependent on the time integral of the error signal and incorporating the damping term, the control signal being applied to the oscillator to control its frequency, and controllable phase shifting means effective on the oscillation from the oscillator, the phase shifting means being controlled by the control signal, the first and second oscillations being derived directly from the output of the oscillator and from the output of the phase shifting means respectively.
Claim 4
Dependent Claim
83 words
Apparatus according to claim 1, including integrating means responsive to the error signal to produce a control signal dependent on the time integral of the error signal without a damping term, and the means for producing first and second oscillations includes a of controllable frequency oscillator responsive to the control signal to generate the second oscillation and a phase shifter effective on second oscillation from the output of the frequency controllable oscillator and responsive to the control signal to produce the first oscillation.
Claim 5
Dependent Claim
99 words
Apparatus according to claim 1, in which the means for forming the regenerated signals includes first and second bistable trigger circuits, the first trigger circuit being connected to receive the input digital signals and to be switched in response to the first oscillation to states dependent on the input digital signals, and the second trigger circuit being connected to the first trigger circuit and to be switched in response to the second oscillation to states dependent on those of the first trigger circuit, the regenerated signals being derived from a connection to an output of the second trigger circuit.
Claim 6
Dependent Claim
99 words
Apparatus according to claim 2, in which the means for forming the regenerated signals includes first and second bistable trigger circuits, the first trigger circuit being connected to receive the input digital signals and to be switched in response to the first oscillation to states dependent on the input digital signals, and the second trigger circuit being connected to the first trigger circuit and to be switched in response to the second oscillation to states dependent on those of the first trigger circuit, the regenerated signals being derived from a connection to an output of the second trigger circuit.
Claim 7
Dependent Claim
99 words
Apparatus according to claim 3, in which the means for forming the regenerated signals includes first and second bistable trigger circuits, the first trigger circuit being connected to receive the input digital signals and to be switched in response to the first oscillation to states dependent on the input digital signals, and the second trigger circuit being connected to the first trigger circuit and to be switched in response to the second oscillation to states dependent on those of the first trigger circuit, the regenerated signals being derived from a connection to an output of the second trigger circuit.
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) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |