Patent ID: 7548118

Claim:
A semiconductor device comprising a plurality of high frequency amplifier circuits connected in parallel between an input terminal and an output terminal, wherein each of the amplifier circuits includes a bipolar transistor, a collector of the bipolar transistor being connected to the output terminal, an oscillation stabilizing circuit connected between the input terminal and a base of the bipolar transistor, the oscillation stabilizing circuit having a resistive component for low frequency signals and a substantially short-circuited component for high frequency signals, and a ballast circuit for preventing thermorunaway of the bipolar transistor, one end of the ballast circuit being connected to a bias terminal, the other end being connected to a point between the oscillation stabilizing circuit and the base of the bipolar transistor, wherein a distortion reducing resistor for reducing distortion of high frequency signals at the output terminal is connected between the input terminal and the bias terminal.