Gain control methods and systems in an amplifier assembly
AssigneeBroadcom Corporation
InventorsLeonard Dauphinee, Lawrence M. Burns
Life of this patent
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Abstract
A Variable Gain Amplifier (VGA) amplifies an input signal according to a gain, to produce an amplified signal. A detector module detects a power indicative of a power of the amplified signal. A comparator module compares the detected power to a high threshold, a low threshold and a target threshold intermediate the high and low thresholds. A controller module changes the gain of the VGA so as to drive the detected power in a direction toward the middle threshold when the comparator module indicates the detected power is not between the high and low thresholds.
Claims32
An Automatic Gain Control (AGC) method, comprising:
- (a) amplifying an input signal using a Variable Gain Amplifier (VGA) with a plurality of parallel gain stages, the VGA gain being a sum of gains of the plurality of gain stages, to produce an amplified output signal;
- (b) detecting a power of the amplified output signal;
- (c) determining if the detected power is between a high threshold and a low threshold;
- and
- (d) changing the gain so as to drive the detected power in a direction toward a target threshold between the high and low thresholds when the detected power is determined in step (c) to be not between the high and low thresholds.
An Automatic Gain Control (AGC) system, comprising:
- a Variable Gain Amplifier (VGA) configured to amplify an input signal according to a gain, to produce an amplified signal,
- wherein the VGA includes a plurality of parallel gain stages, the VGA gain being a sum of gains of the plurality of gain stages;
- a detector configured to detect a power indicative of a power of the amplified signal;
- a comparator module configured to compare the detected power to a high threshold, a low threshold and a target threshold intermediate the high and low thresholds;
- and
- a controller module configured to change the gain of the VGA so as to drive the detected power in a direction toward the target threshold when the comparator module indicates the detected power is not between the high and low thresholds.
Dependencies are inferred from the claim text.