Amplifier; and transmitter and communication device incorporating the same

摘要

The present invention provides an amplifier for amplifying a high-frequency signal and outputting an amplified signal. The amplifier includes: an amplification element which is a bipolar transistor or a field-effect transistor; and an inductor connected between a base and a collector or between a gate and a drain of the amplification element. The inductance of the inductor is chosen so that, within a predetermined frequency range, a parallel resonance occurs with a parasitic capacitor of the amplification element and an intrinsic capacitor of the amplification element, the intrinsic capacitor being a base-collector capacitance or a gate-drain capacitance.