POWER AMPLFIER

摘要

PURPOSE: A power amplifier is provided to increase linearity by suppressing the phase variation of an output signal according to an input signal level variation by varying impedance between a signal input part and an amplifier unit according to the power level of an input signal. CONSTITUTION: A power amplifier includes a bias voltage generation unit(110), an impedance varying unit(120) and an amplifier unit(130). The bias voltage generation unit generates a bias voltage set according to the power level of an input signal. The amplifier unit amplifies the power level of the input signal according to the bias voltage. The impedance varying unit varies the impedance of a signal transfer path to transmit the input signal to the amplifier unit according to the bias voltage. [Reference numerals] (110) Bias voltage generation unit; (120) Impedance varying unit; (130) Amplifier unit; (140) Input impedance matching unit; (150) Output impedance matching unit