Power amplifier

A power amplifier comprising:

• a first amplifier configured to amplify a first high-frequency signal;
• a second amplifier configured to amplify a second high-frequency signal, the second high-frequency signal being delayed with respect to the first high-frequency signal by at least 90 degrees;
• a hybrid coupler comprising a first transmission line and a second transmission line;
• a first power-supply circuit configured to supply electric power to the first amplifier;
• a second power-supply circuit configured to supply the electric power to the second amplifier;
• and
• an output matching network,
• wherein the hybrid coupler is:
• connected to an output end of the first amplifier at a first end of the first transmission line,
• connected to the first power-supply circuit and the output matching network at a second end of the first transmission line,
• connected to an output end of the second amplifier at a first end of the second transmission line, and
• connected to the second power-supply circuit at a second end of the second transmission line.