US3835393A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Duplex cable communications network employing automatic gain control utilizing a band limited noise agc pilot
Assignee: Jerrold Electronics Corp
•
Filing: 1972-04-17
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Granted: 1974-09-10
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Expires: 1992-04-17
Abstract
Abstract A full duplex private communications network provides independent automatic gain control circuitry for the oppositelypropagating signals. Band limited white noise is used to effect automatic gain control for information converging in the distribution network towards common head end equipment. Automatic gain control for this reverse direction propagation is thereby made insensitive to frequency and phase perturbations of any AGC pilot, and also performs well notwithstanding malfunctions in system communications links.
Inventors
- 👤 H Marron
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:28
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04N; H04N7/00; H04N7/16; H04N7/173
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
124 words
In combination in a cable television bidirectional signal propagating system wherein plural first system signal propagating channels converge into a second system signal propagating channel at a convergence point for conveying signals in a cable network in a reverse direction toward a cable system head end, at least one variable gain repeater amplifier included in each of said first and second system signal propagating channels, means for supplying a prescribed frequency band of noncoherent noise signals to the input of said repeater amplifier in each of said first signal propagating channels, and automatic gain control circuit means included in each of said repeater amplifiers for adjusting the gain of the associated repeater amplifier responsive to the amplitude of the noise signal at said amplifier.
Claim 2
Dependent Claim
124 words
In combination in a cable television bidirectional signal propagating system wherein plural first system signal propagating channels converge into a second system signal propagating channel at a convergence point for conveying signals in a cable network in a reverse direction toward a cable system head end, at least one variable gain repeater amplifier included in each of said first and second system signal propagating channels, means for supplying a prescribed frequency band of noncoherent noise signals to the input of said repeater amplifier in each of said first signal propagating channels, and automatic gain control circuit means included in each of said repeater amplifiers for adjusting the gain of the associated repeater amplifier responsive to the amplitude of the noise signal at said amplifier.
Claim 3
Dependent Claim
19 words
A combination as in claim 1 wherein said noncoherent noise signal supplying means includes means for supplying white noise.
Claim 4
Dependent Claim
44 words
A combination as in claim 1 wherein said automatic gain control circuit means includes feedback means comprising band pass filter means for passing a part of the noise band supplied by said noncoherent noise signal supplying means, a noise detector, and additional amplifier means.
Claim 5
Dependent Claim
35 words
A combination as in claim 1 further comprising head end video signal supplying means connected to said second system signal propagating channel, wherein said signal propagating channels further comprise means for amplifying said video signals.
Claim 6
Dependent Claim
44 words
A combination as in claim 1 further comprising band attenuating means associated with and coupled to one amplifier in each of said first signal propagating channels, said attenuating means attenuating signals of the same frequency range as that of the noise signal supplying means.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |