A Doherty power amplifier including a main amplifier, an auxiliary amplifier and a controller governing the operation of the auxiliary amplifier, the controller being operative to switch the operational state of the auxiliary amplifier between an operational state and a non-operational state as a function of input signal voltage supplied to the power amplifier such that the auxiliary amplifier is inoperative when the input voltage is below an input voltage threshold and is operative when the input voltage is above the input voltage threshold.