OUTPUT CONTROL SYSTEM FOR POWER AMPLIFIER

PURPOSE:To optimize the output control of a power amplifier and the power consumption control by storing an output power characteristic of a transistor (TR) of the power amplifier to each input/output bias voltage to a memory in advance. CONSTITUTION:A power supply voltage for bias is impressed to a terminal 19. In applying an output power designation signal at a terminal 18 as a form of a digital signal in 5-bit, a bias voltage to obtain an output power is read from a memory circuit of a bias control circuit 17 and its signal is outputted to terminals 14-16. The input/output bias voltage fed to the power amplifier 1 is controlled to control voltages 11-16 by a power voltage at a terminal 19 and a bias control circuit 10. Each input/output bias voltage to obtain a required output power is selected minimizingly and the voltage is stored in a memory circuit, allowing to operate the power amplifier at the highest efficiency.