Power amplifier, and a base station radio remote unit

There is provided a power amplifier comprising an envelope modulator (101), a main power amplifier (102) and an auxiliary power amplifier (103), wherein the envelope modulator (101), respectively, with the main amplifier ( drain 102) and the drain of the auxiliary amplifier (103) is connected, for obtaining an envelope voltage based on the received envelope signal, respectively, said auxiliary amplifier to the main amplifier (102) and ( 103) of said drain output envelope voltage; said main amplifier (102), and to the envelope modulator (101) is connected, in the operating state is used, from the envelope modulator ( 101) receiving the envelope voltage as an operating voltage, the source electrode of the main power amplifier for amplifying the input process; the auxiliary amplifier (103), in parallel with the main amplifier (102), and the envelope modulator (101) is connected, in the operating state is used, from the envelope modulator (101) receives the envelope voltage as an operating voltage, the auxiliary amplifier ( signal 103) input source enlargement processing.