HIGH-EFFICIENT POWER AMPLIFIER

摘要

PURPOSE: A high-efficient power amplifier is provided to enhance the efficiency by controlling a bias voltage and changing the load impedance according to each operation level. CONSTITUTION: A high-efficient power amplifier includes an input terminal and an output terminal to amplify a received signal and output the amplified signal. The high-efficient power amplifier further includes a bias control unit and an impedance matching unit. The bias control unit(330) is connected to the input terminal in order to control a bias voltage applied to the input terminal. The impedance matching unit(350) is connected between the output terminal and a load resistance in order to change a load impedance value of the power amplifier. The bias control unit sets up the bias voltage at a back-off point of the power amplifier in a maximum power mode and applies lower voltage than the bias voltage to the power amplifier in a normal mode. The impedance matching unit sets up the load impedance at OP1dB in the maximum power mode and changes the load impedance to the lower impedance than the load impedance in the normal mode.