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US4667163A Expired / Lapsed US ⏱️ 0.0 years remaining

Automatic gain control circuit

Assignee: Motorola Solutions Inc
•
Filing: 1985-06-06
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Granted: 1987-05-19
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Expires: 2005-06-06
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Abstract

Abstract An automatic gain control circuit (e.g. for use in a SECAM television receiver) comprising: an input node (2); an output node (40); controllable gain amplifier means (6) having a signal input (4) connected to the input node, a control input (24) and an output (8); automatic gain control means (20) having an input (18) coupled to the output of the controllable gain amplifier means and an output (22) connected to the control input of the controllable gain amplifier means; and divider means (30) having a first signal input (28) coupled to the output of the controllable gain amplifier means, a divide signal input (36) coupled to the input of the automatic gain control means and an output connected to the output node of circuit, whereby the signal produced at the output of the divider means is substantially independent of the signal level produced at the output of the controllable gain amplifier means.

Inventors

  • 👤 Michael J. Gay

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 06:04
CPC Classifications
H; H03; H03G; H03G3/00; H03G3/20; H03G3/30; H04; H04N; H04N11/00; H04N11/06; H04N11/18; H04N11/186; H03D; H03D3/00; H03D3/02; H03G3/3052; H03G3/3068; H04N5/00; H04N5/44; H04N5/52

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 50 words
An automatic gain control circuit comprising: a controllable gain amplifier having a signal input operating as a input node of the automatic gain control circuit, a control input, and an output; a multiplier having first and second inputs coupled at the output of said controllable gain amplifier and an output;
Claim 2
Dependent Claim 50 words
An automatic gain control circuit comprising: a controllable gain amplifier having a signal input operating as a input node of the automatic gain control circuit, a control input, and an output; a multiplier having first and second inputs coupled at the output of said controllable gain amplifier and an output;
Claim 3
Dependent Claim 70 words
an AGC gain generator having an input coupled to the output of said multiplier and an output coupled to the control input of said controllable gain amplifier; and a multiplier/divider circuit having first and second multiplier inputs coupled to the output of said controllable gain amplifier, a divider input coupled to the output of said multiplier, and an output operating as an output node of the automatic gain control circuit.
Claim 4
Dependent Claim 70 words
an AGC gain generator having an input coupled to the output of said multiplier and an output coupled to the control input of said controllable gain amplifier; and a multiplier/divider circuit having first and second multiplier inputs coupled to the output of said controllable gain amplifier, a divider input coupled to the output of said multiplier, and an output operating as an output node of the automatic gain control circuit.
Claim 5
Dependent Claim 38 words
An automatic gain control circuit as claimed in claim 1 wherein one of the first and second multiplier inputs of said multiplier/divider circuit is coupled through a phase shifting filter to the output of said controllable gain amplifier.
Claim 6
Dependent Claim 59 words
An automatic gain control circuit as claimed in claim 2 wherein the divider input of said multiplier/divider circuit is coupled through a low pass filter to the output of said multiplier and signal delays produced by said low-pass filter and said phase shifting filter are substantially matched to minimize differential delay effects at the output of said multiplier/divider circuit.
Claim 7
Dependent Claim 34 words
An automatic gain control circuit as claimed in claim 1 wherein said controllable gain amplifier, said multiplier, said AGC gain generator, and said multiplier/divider circuit are included in an integrated circuit with associated circuitry.
Claim 8
Dependent Claim 32 words
An automatic gain control circuit as claimed in claim 1 wherein said controllable gain amplifier, said multiplier, said AGC gain generator, and said multiplier/divider circuit are included in a SECAM television receiver.

References Cited (Backward Citations)

EP0003393A1 Cited
GB2064253A Cited
DD156655A1 Cited
US4563653A Cited
JPS5974710A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-05-18 1990-11-17 1991-05-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-05-18 1994-11-17 1995-05-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-05-18 1998-11-17 1999-05-19 $7700.00 Window Closed / Lapsed

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