POWER AMPLIFIER WITH AUTOMATICALLY SWITCHING FACILITY

摘要

A power amplifier with automatically switching function is provided to vary output by operating whole parts of a circuit by turning on in case of requiring high power and stopping a portion of the circuit by turning off in case of requiring low power according to a magnitude of an envelop signal. In a power amplifier consisting of a plurality of power amplifying terminals receiving an envelop signal with automatically switching function, a plurality of switching circuits turns on/off the plurality of power amplifying terminals, wherein the switching circuits mounted at a front terminal of each of the power amplifying terminals or at each of the power amplifying terminals is individually switched in accordance with a magnitude of the envelop signal inputted by the respective reference voltages.