Power amplifier circuit having a bias signal inputted into input terminal and method thereof

摘要

The present invention discloses an adjustable gain power amplifier circuit. The adjustable gain power amplifier circuit includes a power amplifying unit for receiving and amplifying an input signal to generate an output signal; a power detecting unit for detecting power of the input signal to generate a detecting signal; and a biasing control unit for generating a biasing signal according to the detecting signal and to output the biasing signal.