Doherty amplifier

A Doherty amplifier comprising:

• a first amplifier that amplifies an RF input signal according to a voltage applied to a supply terminal thereof;
• a second amplifier that amplifies a peak component of the RF input signal according to a voltage applied to a supply terminal thereof;
• a transmission line coupled to an output terminal of the first amplifier;
• a synthesizer that is coupled to an output terminal of the transmission line and an output terminal of the second amplifier, and synthesizes an output signal of the transmission line and an output signal of the second amplifier;
• and
• an output load coupled to an output terminal of the synthesizer, wherein
• it is set such that the voltage applied to the supply terminal of the first amplifier is lower than the voltage applied to the supply terminal of the second amplifier, and that an impedance value of the transmission line is smaller than a value twice an impedance value of the output load.