AMPLIFIER CIRCUIT

摘要

An amplifier circuit includes a pair of amplifying devices, a first balun coupled between an amplifier circuit input port and RF input ports of the amplifying devices and a second balun coupled between RF output ports of the amplifying devices and an amplifier circuit output port. The first and second baluns configured such that the amplifier circuit rejects or attenuates signals at a second harmonic frequency even when the second harmonic frequency is within an operating frequency band of the amplifier circuit. The amplifier circuit may include a bypass circuit which selectively presents impedances to balun ports and in response to a first control signal, the amplifier circuit operates in an amplifying mode and in response to a second control signal, the amplifier circuit operates in a bypass mode. The amplifier circuit may include bias circuits which provide DC bias signals to the amplifying devices through the baluns.