US3763490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Adaptive beamformer with time constant control
Assignee: General Electric Co
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Filing: 1971-12-10
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Granted: 1973-10-02
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Expires: 1991-12-10
Abstract
Abstract An adaptive beamformer and signal processor for sonar and other signal receptor arrays, in which beamforming is accomplished by correlation feedback loops providing matched weighting across the array. For improved performance of the adaptive beamformer thus comprised in the presence of large input transients, while preserving its steady state performance essentially unchanged, the time constant of the correlation feedback loops is placed under automatic control and adjusted thereby to prevent saturation of the loops even with large interference transients.
Inventors
- 👤 H Hadley
- 👤 D Saum
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:40
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/02; H04B7/04; H04B7/08; H04B7/0837; H04B7/0842; H04B7/086; H01; H01Q; H01Q3/00; H01Q3/26; H01Q3/2605; H01Q3/2611; H01Q3/2617
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
141 words
In combination with an array of wave receptors, an adaptive array beamformer compRising primary beamformer means for phase and amplitude weighting the elemental signals of said array with nominal weights so as to form and direct a beam mainlobe to the angle of desired maximum response of the array, auxiliary, beamformer means including a plurality of feedback correlation loops each having as inputs the beamformer output and one of said elemental signals and being operative to derive therefrom a perturbation weight and to output a signal which is phase and amplitude weighted thereby so as to form and direct a null to the angle of arrival of interference, means for adjusting the correlation feedback loop time constant, and means responsive to said elemental signals for controlling said time constant adjustment means so as to avoid loop saturation with large interference transients.
Claim 2
Dependent Claim
141 words
In combination with an array of wave receptors, an adaptive array beamformer compRising primary beamformer means for phase and amplitude weighting the elemental signals of said array with nominal weights so as to form and direct a beam mainlobe to the angle of desired maximum response of the array, auxiliary, beamformer means including a plurality of feedback correlation loops each having as inputs the beamformer output and one of said elemental signals and being operative to derive therefrom a perturbation weight and to output a signal which is phase and amplitude weighted thereby so as to form and direct a null to the angle of arrival of interference, means for adjusting the correlation feedback loop time constant, and means responsive to said elemental signals for controlling said time constant adjustment means so as to avoid loop saturation with large interference transients.
Claim 3
Dependent Claim
79 words
An array beamformer as defined in claim 1 wherein said means responsive to said elemental signals derives therefrom an average received power level signal, and includes sampled-data exponential filter means through which said power level signal is processed to introduce a weighting function such that said correlation loop time constant adjustment means responds to power level transients to adjust said time constant to maintain correlation loop stability and does not thus respond to steady state changes in power level.
Claim 4
Dependent Claim
36 words
An array beamformer as defined in claim 2 wherein said sampled-data exponential filter means includes a signal recirculation loop providing delay equal to the sampling interval and gain such as to yield the desired weighting function.
Claim 5
Dependent Claim
32 words
An array beamformer as defined in claim 3, further including means for varying the gain of said control signal to obtain the desired steady state value of correlation feedback loop time constant.
Claim 6
Dependent Claim
79 words
An array beamformer as defined in claim 1 wherein said means responsive to said elemental signals for controlling said time constant adjustment means comprises means for deriving from at least one of said elemental signals a control signal varying with the difference of instantaneous and time-averaged power levels thereof, and wherein said means for adjusting the correlation feedback loop time constant comprises loop gain control means operative to adjust loop gain in response to the control signal thus derived.
References Cited (Backward Citations)
US3177489A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-01 | 1977-04-02 | 1977-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-01 | 1981-04-02 | 1981-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-01 | 1985-04-02 | 1985-10-02 | $7700.00 | Window Closed / Lapsed |