Patent ID: 8564366

Claim:
A high-frequency power amplifier device comprising: a first power amplifier circuit that amplifies a first input signal; a second power amplifier circuit that amplifies the first input signal; a first transmission line that is coupled at one end to an output node of the first power amplifier circuit; a first capacitance that is coupled to the other end of the first transmission line; a second transmission line that is coupled at one end to the output node of the first power amplifier circuit and coupled at the other end to an output node of the second power amplifier circuit; a second capacitance and a transistor switch that are disposed in series between the output node of the second power amplifier circuit and a ground supply voltage; and a control circuit that activates either the first power amplifier circuit or the second power amplifier circuit in accordance with a mode setup signal, drives the transistor switch to turn off when the first power amplifier circuit is activated, and drives the transistor switch to turn on when the second power amplifier circuit is activated, wherein the first and second transmission lines include a magnetic coupling region that is positioned close to the first and second transmission lines to cause magnetic coupling, and wherein, in the magnetic coupling region, the first and second transmission lines are disposed so that the first transmission line originating from the output node side of the first power amplifier circuit is extended in the same direction as the second transmission line originating from the output node side of the second power amplifier circuit.