High frequency power amplifier circuit

A high-frequency power amplifier circuit comprising:

• an output circuit with a plurality of cascaded semiconductor devices;
• a bias circuit that drives the semiconductor amplifier devices according to a control voltage;
• and
• semiconductor devices that are arranged so as to construct current mirror circuits with the plurality of semiconductor amplifier devices,
• wherein the bias circuit includes a voltage-to-current converter that converts a control voltage to current;
• a first resistance for converting current supplied from the voltage-to-current converter to a voltage;
• a first current source;
• a first semiconductor amplifier device connected to the first current source in series;
• a control voltage generator that generates a voltage equal to the threshold voltage of the first semiconductor amplifier device;
• and a second semiconductor amplifier device that generates current responsive to the combination of a voltage generated in the control voltage generator and a voltage converted by the first resistance, wherein a current with a characteristic responsive to current flowing into the second semiconductor amplifier device is supplied to the semiconductor devices arranged so as to form the current mirror circuits, and the semiconductor amplifier device is driven by the current.