US3919653A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic frequency corrector for differential phase demodulator
Assignee: LANNIONNAIS ELECTRONIQUE
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Filing: 1974-04-22
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Granted: 1975-11-11
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Expires: 1994-04-22
Abstract
Abstract Correcting device ensuring automatically, at the receiving end, an exact timing of the frequency demodulated at the rated value, that timing being necessary for the demodulation to be effected correctly, the correction being effected by a frequency servocontrolling based on an error signal extracted from a frequency discriminator, by means of a processing of decoded logic signals.
Inventors
- 👤 Mouel Bernard Le
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:20
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/18; H04L27/22
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
150 words
An automatic frequency corrector for a frequency servocontroller for frequency transposition in a demodulator of a wave modulated by differential phase, comprising a phase discriminator receiving on one input said modulated wave and on a second input the same modulated wave delayed by a time Tau , said phase discriminator providing at its output a first bipolar signal, a demodulator receiving said modulated wave, a first decoder connected to said demodulator for providing binary signals corresponding to the positive portions of said bipolar signal, a second decoder connected to said demodulator providing binary signals corresponding to the negative portions of said bipolar signal, a first subtractor responsive to the outputs of said first and second decoders for providing a second bipolar signal, a second subtractor connected to receive said first and second bipolar signals, and means for connecting the output of said second subtractor in control of said frequency servo-controller.
Claim 2
Dependent Claim
150 words
An automatic frequency corrector for a frequency servocontroller for frequency transposition in a demodulator of a wave modulated by differential phase, comprising a phase discriminator receiving on one input said modulated wave and on a second input the same modulated wave delayed by a time Tau , said phase discriminator providing at its output a first bipolar signal, a demodulator receiving said modulated wave, a first decoder connected to said demodulator for providing binary signals corresponding to the positive portions of said bipolar signal, a second decoder connected to said demodulator providing binary signals corresponding to the negative portions of said bipolar signal, a first subtractor responsive to the outputs of said first and second decoders for providing a second bipolar signal, a second subtractor connected to receive said first and second bipolar signals, and means for connecting the output of said second subtractor in control of said frequency servo-controller.
Claim 3
Dependent Claim
35 words
An automatic frequency corrector as defined in claim 1, further including a low-pass filter connected between each of said first and second decoders and the inputs of said first subtractor to which they are connected.
Claim 4
Dependent Claim
30 words
An automatic frequency corrector as defined in claim 2 wherein a further low-pass filter is connected between the output of said phase discriminator and the input of said second subtractor.
Claim 5
Dependent Claim
36 words
An automatic frequency corrector as defined in claim 3 wherein the inputs of said phase discriminator and said demodulator are derived from respective outputs of a power divider connected to the output of said frequency servocontroller.
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) | 1978-11-10 | 1979-05-12 | 1979-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-10 | 1983-05-12 | 1983-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-10 | 1987-05-12 | 1987-11-11 | $7700.00 | Window Closed / Lapsed |