Patent US3285704A successfully refreshed from Google Patents.
Patent US5084899A successfully refreshed from Google Patents.
US5084899A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal suppressors
Assignee: BAE Systems Electronics Ltd
•
Filing: 1980-11-28
•
Granted: 1992-01-28
•
Expires: 2000-11-28
Abstract
Abstract An interference suppressor comprises an amplitude limiter (2) to which a received signal is coupled. The limiter (2) is effective, when a dominant interfering signal (f1) is present together with a wanted signal (f1), to further increase the amplitude difference between interfering and wanted signals. A signal combiner (12) is fed with the received signal and also with a signal derived from the limiter (2) via a controlled attenuator (9) and which signal is arranged as to be in phase opposition to the received signal. A phase sensitive detector (8) is responsive to the output signal from the suppressor, which is provided by the signal combiner (12), and to the signal derived from the limiter (2) for providing a control signal for the attenuator (9). The control signal is effective to reduce the amplitude of the interfering signal present in the output signal.
Inventors
- 👤 David Harrington
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 04:07
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/12; H04B1/123
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
123 words
An interference suppressor, comprising amplitude limiter means to which a received signal comprising a wanted signal and a dominant interfering signal is fed so as further to increase the amplitude differential therebetween, signal combiner means fed with the received signal and fed also via a controlled attenuator with a signal derived from the limiter which is in phase opposition to the received signal, and a phase sensitive detector responsive to an output signal from the suppressor provided by the signal combiner means and to the signal derived from the limiter for providing a control signal for the attenuator effective to control the said attenuator so that the amplitude of the interfering signal present in the output signal from the suppressor tends towards zero.
Claim 2
Dependent Claim
123 words
An interference suppressor, comprising amplitude limiter means to which a received signal comprising a wanted signal and a dominant interfering signal is fed so as further to increase the amplitude differential therebetween, signal combiner means fed with the received signal and fed also via a controlled attenuator with a signal derived from the limiter which is in phase opposition to the received signal, and a phase sensitive detector responsive to an output signal from the suppressor provided by the signal combiner means and to the signal derived from the limiter for providing a control signal for the attenuator effective to control the said attenuator so that the amplitude of the interfering signal present in the output signal from the suppressor tends towards zero.
Claim 3
Dependent Claim
23 words
An interference suppressor as claimed in claim 1, including an integrator connected in circuit between the phase sensitive detector and the controlled attenuator.
Claim 4
Dependent Claim
29 words
An interference suppressor as claimed in claim 1 or 2, including a band pass filter connected in circuit between the limiter the phase sensitive detector and the controlled attenuator.
Claim 5
Dependent Claim
30 words
An interference suppressor as claimed in claim 1 or 2 or 3, wherein the signal combiner means comprises a bridge circuit operable to cancel additional frequencies produced within the suppressor.
Claim 6
Dependent Claim
35 words
A spread spectrum communication system, comprising a transmitter including a spread spectrum signal generating means, and a receiver comprising an interference suppressor as claimed in any one of the preceding claims and signal despreading means.
Claim 7
Dependent Claim
100 words
A communication system as claimed in claim 5, wherein the spread spectrum signal generating means comprises a digital code generator, a mixer having a first input for an information signal, a second input coupled with the digital code generator and an output for the spread spectrum signal, and the despreading means comprises means for providing a digital code signal identical to and in synchronism with the signal of said digital code generator and a mixer having a first input for the received signal a second input fed with said identical code signal and an output for a despread received signal.
References Cited (Backward Citations)
US3747100A
Cited
US3906411A
Cited
US4057802A
Cited
US4097866A
Cited
US4105977A
Cited
US4156877A
Cited
US4152702A
Cited
US4298871A
Cited
US4363138A
Cited
US4538280A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-01-27 | 1995-07-29 | 1996-01-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-01-27 | 1999-07-29 | 2000-01-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-01-27 | 2003-07-29 | 2004-01-28 | $7700.00 | Window Closed / Lapsed |