Patent ID: 8923436

Claim:
A transmitter comprising: an RF signal generator that divides an input radio signal into an amplitude signal and a phase signal and outputs the amplitude signal and the phase signal; and a switching amplifier that amplifies the radio signal with the amplitude signal and the phase signal, wherein the switching amplifier comprises: at least one variable current source that is controlled by the amplitude signal and supplies a current to the switching amplifier; and at least one switching element that connects the variable current source to one of a ground potential and an output terminal of the switching amplifier according to the phase signal, and wherein the switching amplifier comprises: first and second variable current sources; a first switching element that connects the first variable current source to one of a ground potential and a first output terminal of the switching amplifier according to the phase signal; and a second switching element that connects the second variable current source to one of the ground potential and a second output terminal of the switching amplifier according to a signal complementary to the phase signal.