High-power amplifier and multi-stage high-power amplifier

摘要

PPROBLEM TO BE SOLVED: To obtain a high-output amplifier being miniaturized and having small loss for the output power. PSOLUTION: The high-output amplifier has a main amplifier 2 amplifying a high-frequency signal input, in response to the base current, the base bias circuit 5 for controlling the base current of the main amplifier 2, in response to a differential current Iset-Ifb and a reference circuit 6 for generating a reference current Iset corresponding to the reference voltage Vset of a reference power supply 7. The high-output amplifier further has a detector 8 detecting the base current of the base bias circuit 5 and generating a feedback current Ifb, where the detecting current is level-adjusted by the reference current of the reference circuit 6 and a current comparison circuit 9 feeds back the differential current Iset-Ifb, level-adjusted by the reference current Iset of the reference circuit 6 and the detector 8, to the base bias circuit 5. Since the base current of the base bias circuit 5, controlling the base current of the main amplifier 2, is detected, the high-output amplifier can be miniaturized, and loss of the output power is reduced without having to use a distributor. PCOPYRIGHT: (C)2007,JPO&INPIT