US5697086A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Co-channel FM signal/interference canceller
Assignee: General Dynamics Government Systems Corp
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Filing: 1994-04-15
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Granted: 1997-12-09
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Expires: 2014-04-15
Abstract
Abstract A combination of two phase-lock loops, and a cancellation circuit are used to remove a dominant FM signal from within a signal environment. The two phase-lock loops together produce a replica of the highest power (i.e. dominant) FM signal. The cancellation circuit uses this replica in a demodulation, notch-filtering, and remodulation process to excise the dominant FM signal, leaving the other signal(s) undisturbed. Potential applications include co-channel FM signal/interference cancellation and optimizing utilization of RF spectrum.
Inventors
- 👤 Esteban O. Svoboda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:36
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/12; H04B1/123
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
180 words
A device for removing a dominant FM signal from within a set of input signals occupying the same frequency band, comprising in combination: a) FM demodulation means for recovering the modulating signal of a received dominant FM carrier signal; b) FM modulation means for generating a replica of the received dominant FM carrier signal using the output of said FM demodulation means as the modulating signal; c) delay means for aligning in time the original signal input to a replica of the dominant FM signal generated by said FM modulation means; and d) cancellation means for removing the dominant FM signal from a set of input signals occupying the same frequency band; said cancellation means comprising: means to demodulate said dominant FM signal to a single spectral line; means to filter out said spectral line to produce the cross-products of the dominant FM signal and underlying signals; and means to multiply said signal cross-products with the dominant FM signal again to obtain a signal which contains all of the original underlying signal or signals without the dominant FM signal present.
Claim 2
Independent Claim
180 words
A device for removing a dominant FM signal from within a set of input signals occupying the same frequency band, comprising in combination: a) FM demodulation means for recovering the modulating signal of a received dominant FM carrier signal; b) FM modulation means for generating a replica of the received dominant FM carrier signal using the output of said FM demodulation means as the modulating signal; c) delay means for aligning in time the original signal input to a replica of the dominant FM signal generated by said FM modulation means; and d) cancellation means for removing the dominant FM signal from a set of input signals occupying the same frequency band; said cancellation means comprising: means to demodulate said dominant FM signal to a single spectral line; means to filter out said spectral line to produce the cross-products of the dominant FM signal and underlying signals; and means to multiply said signal cross-products with the dominant FM signal again to obtain a signal which contains all of the original underlying signal or signals without the dominant FM signal present.
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) | 2000-12-08 | 2001-06-09 | 2001-12-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-12-08 | 2005-06-09 | 2005-12-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-12-08 | 2009-06-09 | 2009-12-09 | $7700.00 | Window Closed / Lapsed |