Patent US3605012A successfully refreshed from Google Patents.
US3605012A
Expired / Lapsed
US
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Noise cancellation filter system
Assignee: United States Department of the Army
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Filing: 1969-07-15
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Granted: 1971-09-14
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Expires: 1989-07-15
Abstract
Abstract There is provided a system which detects a desired signal in the presence of random noise. A plurality of filters having successively adjacent passbands simultaneously receive a composite of noise and desired signal. Each filter passes only that portion of the composite within its respective passband. All portions are then integrated and thereafter alternate portions are inverted. Inverted and noninverted portions are then summed, the desired signal, if present, appearing as a residue. Sensing indicators connected to each summer output then indicate within which filter the desired signal appeared.
Inventors
- 👤 Jacob H Kubanoff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 23:45
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/02; H; H03; H03H; H03H7/00; H03H7/46; H04; H04B; H04B1/00; H04B1/06; H04B1/10; H04B1/12; H04B1/123
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
196 words
A noise cancellation circuit for separating the intelligence portion from the noise of a transmission within a frequency spectrum which circuit comprises: a plurality of channels, each channel having connected therein; a first band-pass filter for passing only therethrough a first narrow frequency band, a second band-pass filter for passing only therethrough a second narrow frequency band equal in bandwidth to and frequency contiguous said first narrow frequency band and having a common boundary therewith, wherein each of said channels encompasses a different region of said frequency spectrum, a pair of identical integrators, an inverter, a summing means having a pair of inputs and one output for providing an output signal which is the sum of the input signals, a first circuit path having connected in series therein said first band-pass filter, one of said integrators and one input of said summing means, a second circuit path having connected in series therein said second band-pass filter, the other of said integrators, said inverter, and the other input of said summing means, whereby, when said transmission is applied simultaneously to the inputs of said filters the output of said summing means will be only said intelligence portion.
Claim 2
Dependent Claim
196 words
A noise cancellation circuit for separating the intelligence portion from the noise of a transmission within a frequency spectrum which circuit comprises: a plurality of channels, each channel having connected therein; a first band-pass filter for passing only therethrough a first narrow frequency band, a second band-pass filter for passing only therethrough a second narrow frequency band equal in bandwidth to and frequency contiguous said first narrow frequency band and having a common boundary therewith, wherein each of said channels encompasses a different region of said frequency spectrum, a pair of identical integrators, an inverter, a summing means having a pair of inputs and one output for providing an output signal which is the sum of the input signals, a first circuit path having connected in series therein said first band-pass filter, one of said integrators and one input of said summing means, a second circuit path having connected in series therein said second band-pass filter, the other of said integrators, said inverter, and the other input of said summing means, whereby, when said transmission is applied simultaneously to the inputs of said filters the output of said summing means will be only said intelligence portion.
Claim 3
Dependent Claim
30 words
The noise cancellation circuit according to claim 1 further incLuding an OR gate having a plurality of inputs each connected to receive the output of one of said summing means.
Claim 4
Dependent Claim
72 words
The noise cancellation circuit according to claim 2 further including for each channel: a pair of visual signal indicators connected to receive the output of said summing means, a pair of diodes each connected intermediate said summing means and one of said indicators but of a polarity orientation whereby current will flow only in one direction to one of said indicators and in the opposite direction to the other of said indicators.
References Cited (Backward Citations)
US3103009A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |