Patent ID: 8519797
Filing Date: 2013-08-27
Classification: H03F

Abstract:
1. A power amplifier, comprising: a first transistor comprising a gate electrode, a first electrode and a second electrode, wherein the gate electrode is coupled to a signal input terminal of the power amplifier to receive an input signal; a second transistor comprising a gate electrode, a first electrode and a second electrode, wherein the second electrode of the second transistor is connected to the first electrode of the first transistor, and the first electrode of the second transistor is coupled to a signal output terminal of the power amplifier to output an output signal; a first bias voltage generator, coupled to the second transistor, for generating a first bias voltage to bias the gate electrode of the second transistor, wherein the first bias voltage is less than a supply voltage of the power amplifier; and a detecting circuit, coupled to the gate electrode of the first transistor, for detecting an input signal received from the signal input terminal of the power amplifier to generate a second bias voltage to bias the gate electrode of the first transistor without utilizing the output signal.