Patent ID: 7741904
Filing Date: 2010-06-22
Classification: H03G

Abstract:
1. A linear amplifier circuit, comprising: a first matching circuit configured to receive a first signal and to produce a first impedance matched signal; a first power amplifier coupled to the first matching circuit, wherein the first power amplifier is configured to produce a first amplified signal in response to the first impedance matched signal under the control of a first bias signal; a second power amplifier coupled to the first matching circuit, wherein the second power amplifier is configured to produce a second amplified signal in response to the first impedance matched signal under the control of a second bias signal; a biasing circuit configured to produce the first bias signal and the second bias signal, wherein the first power amplifier is configured to be activated by the first biasing signal when the power of the output signal is to exceed a first threshold value, wherein the second power amplifier is configured to be activated by the second biasing signal when the power of the output signal is below a second threshold value; a second matching circuit configured to receive the first amplified signal and the second amplified signal, and to produce an output signal a third matching circuit configured to receive an input signal and to produce a second matched impedance signal in response to the input signal; a driver amplifier configured to amplify the second impedance matched signal to produce the first signal; a phase control circuit in communication with at least one of the driver amplifier, the first power amplifier and the second power amplifier, wherein the phase control circuit is configured to control variations in the phase of the driver amplifier, the first power amplifier and the second power amplifier in an output power range; and a gain control circuit in communication with at least one of the driver amplifier, the first power amplifier and the second power amplifier, wherein the gain control circuit is configured to control variations in gains of the driver amplifier, the first power amplifier and the second power amplifier in an output power range.