Patent ID: 6943624

Claim:
A radio frequency power amplifier, comprising: at least two power amplifier units, having a different saturated output power level from each other, one of the units being in operation by switching; first-stage matching networks, each connected to an output node of respective one of the at least two power amplifier units; and a last-stage matching network, connected between an output terminal and a junction permanently connecting output nodes of the first-stage matching networks together in parallel independently of ON/OFF switching of said at least two power amplifier units, wherein, when any one of the at least two power amplifier units is in operation and the other in stop of operation, the first-stage matching networks and the last-stage matching network are formed so that impedance matching is established between the output impedance of the power amplifier unit in operation and the output characteristic impedance at the output terminal, for each of the at least two power amplifier units, and wherein said last-stage matching network is fixed in a circuit element value thereof independently of ON/OFF switching of said at least two power amplifier units.