US4549143A
Expired / Lapsed
US
⏱️ 0.0 years remaining
F.M. Demodulator with waveform correction circuit
Assignee: US Philips Corp
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Filing: 1984-07-06
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Granted: 1985-10-22
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Expires: 2004-07-06
Abstract
Abstract An F.M. demodulation circuit can be rendered insensitive to amplitude, level and waveform variations of the frequency-modulated carrier signal by using a frequency-demodulator (33,37) tuned to half the frequency of the carrier and preceded by a divide-by-two divider (21).
Inventors
- 👤 Maurice Bouland
- 👤 Wilhelmus A. J. Van Gurp
- 👤 Wilhelmus A. J. M. Zwijsen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:11
CPC Classifications
H; H03; H03D; H03D3/00; H03D3/006; H04; H04N; H04N11/00; H04N11/06; H04N11/18; H04N11/186; H03D2200/00; H03D2200/0041; H03D2200/0064
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
51 words
F.M. demodulator with waveform circuit comprising a tuned F.M. demodulator preceded by a waveform correction circuit for demodulating a carrier whose frequency is modulated by a modulating signal, chacterized in that the waveform correction circuit is a divide-by-two divider and the demodulator is tuned to half the frequency of the carrier.
Claim 2
Dependent Claim
51 words
F.M. demodulator with waveform circuit comprising a tuned F.M. demodulator preceded by a waveform correction circuit for demodulating a carrier whose frequency is modulated by a modulating signal, chacterized in that the waveform correction circuit is a divide-by-two divider and the demodulator is tuned to half the frequency of the carrier.
References Cited (Backward Citations)
US3701030A
Cited
US3863161A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-21 | 1989-04-22 | 1989-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-21 | 1993-04-22 | 1993-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-21 | 1997-04-22 | 1997-10-22 | $7700.00 | Window Closed / Lapsed |