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.
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Provisional Application No. 60/430,061, filed Dec. 2, 2002, entitled "Amplifier Assembly with AGC for a Tuner," incorporated herein by reference in its entirety;
This application is related to U.S. Non-Provisional application Ser. No. 10/353940, filed herewith, entitled "Amplifier Assembly Including Variable Gain Amplifier, Parallel Programmable Amplifiers, and AGC," incorporated herein by reference in its entirety.
The present invention provides systems and methods for asymmetrically varying gain in a low noise amplifier. The amplifier includes a first stage amplifier, a plurality of second stage amplifiers coupled to the first stage amplifier, a comparator coupled to one of the second stage amplifiers, and a controller coupled to the comparator, the first stage amplifier, and the plurality of second stage amplifiers. The controller is configured to produce one or more gain control signals to change the gain of one of the first stage amplifier or the plurality of second stage amplifiers at a plurality of asymmetric rates so as to cause the power of the output signal to move toward one of the threshold values of the comparator. The rate of change of the gain is based on conditions including the gain of the first stage amplifier, gain of a second stage amplifier, and the sampled power level.
A millimetric-wave amplifier arrangement comprises a first amplifier whose output is connected to one input of the second amplifier via an adjustable attenuator. Both amplifiers are integrated on a single substrate.
A system and method of adjusting a sense amplifier to compensate for the process-type of the sense amplifier includes determining a process-type of the sense amplifier. An amplification control parameter is provided to the sense amplifier. The amplification control parameter is adjusted to adjust the sense amplifier according to the process-type of the sense amplifier.
A signal amplifier system is provided for a mobile or portable broadcast receiver. The signal amplifier system includes an operational circuitry, a signal generator and a voltage supply. The signal generator receives a field strength signal that indicates a field strength of at least one broadcast signal. The signal generator outputs a supply voltage control signal based on the field strength signal. The voltage supply provides one of a first supply voltage and a second supply voltage to the operational circuitry in accordance with the supply voltage control signal.
A data receiver includes group envelope detection circuitry that produces a group envelope voltage. The group envelope voltage represents the average envelope of a plurality of amplified data signals. Associated feedback adjusts the gains applied to each data signal to minimize any difference between the group envelope voltage and a reference voltage. The reference voltage is preferably the envelope of a clock signal associated with the data signals.
