POWER AMPLIFIER DEVICE AND PORTABLE COMMUNICATION TERMINAL DEVICE

摘要

PROBLEM TO BE SOLVED: To improve the entire operation efficiency in a power amplifier for switching any one of an input signal amplified to large power and an input signal amplified to medium power and outputting the switched power. SOLUTION: A second amplifying FET 22 for further amplifying the input signal amplified by an amplifying FET 21 and supplying the amplified signal to a first output terminal 51, and a first switching FET 31 for controlling the amplifying FET 22 in a stop state, are provided between the amplifying FET 21 for amplifying an input signal and the output terminal 51. Also, a second switching FET 32 for controlling whether or not an output from a first amplifying FET 21 should be supplied to a second output terminal 52 is provided between the amplifying FET 21 and the output terminal 52. When medium power is outputted, the switching FET 31 controls the amplifying FET 22 in a stop state, thereby reducing power consumption to improve the operation efficiency of the power amplifier. COPYRIGHT: (C)2005,JPO&NCIPI