HIGH FREQUENCY POWER AMPLIFIER CIRCUIT AND WIRELESS COMMUNICATION UNIT, AND WIRELESS COMMUNICATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a wireless communication unit that controls power without using a power control signal from a base station. SOLUTION: The wireless communication unit is provided with a transmission purpose high frequency power amplifier circuit, a detection means that detects the output of the high frequency power amplifier circuit, and an automatic output control circuit that uses information obtained by the detection means to control the output of the high frequency power amplifier circuit. The high frequency power amplifier circuit has an amplifier system having amplifier stages connected between an input terminal and an output terminal and a bias circuit that supplies a bias to transistors(TRs) of each amplifier stage. The bias circuit supplying the bias to the amplifier stages except a final amplifier stage consists of resistive components, supplies a division voltage formed by dividing a received power control signal by resistors to a control terminal of the amplifier stage where the bias voltage indicates a linear characteristic for a low power mode, and the bias circuit supplying the bias to the final amplifier stage is a circuit where the bias voltage indicates a nonlinear characteristic for a high power mode.