Power amplifier device

A power amplifier device comprising:

• a power amplifier circuit comprising:
• a bias switching circuit,
• a first amplifying transistor, and
• a second amplifying transistor,
• wherein the bias switching circuit is configured to switch between a first connection state and a second connection state, the switching being performed based on a control signal,
• wherein in the first connection state, a first power supply end and a supply end are electrically connected, the first power supply end being electrically connected to a regulated power supply that supplies a first voltage that is constant,
• wherein in the second connection state, a second power supply end and the supply end are electrically connected, the second power supply end being electrically connected to a variable power supply that supplies a second voltage that varies,
• wherein the first amplifying transistor is a field effect transistor having a bias end, an output end, and a connection end,
• wherein the bias end is electrically connected to the supply end with a first resistor circuit element interposed between the bias end and the supply end,
• wherein the output end is electrically connected to a power supply,
• wherein the second amplifying transistor is a field effect transistor having an input end, an amplification end, and a ground end,
• wherein the amplification end is connected in series to the connection end of the first amplifying transistor,
• wherein the ground end is electrically connected to ground, and
• wherein the power amplifier circuit is configured to output an amplified signal from the output end of the first amplifying transistor, the amplified signal being obtained by amplifying an input signal input to the input end of the second amplifying transistor.