TRIPLE CLASS E DOHERTY AMPLIFIER TOPOLOGY FOR HIGH EFFICIENCY SIGNAL TRANSMITTERS
A Doherty amplifier circuit is provided comprising at least three class E amplifiers 210 receiving separated amplitude 226 and phase information 224 at least one signal source. At least one first impedance adjustment device is linked between the signal source and the inputs to at least two of the amplifiers, and a plurality of second impedance adjustment devices is linked to the outputs of the amplifiers to combine the outputs into an output of the circuit. In this way, a scheme for efficient amplification of amplitude modulated waveforms is achieved across a wide dynamic range and for a large peak-to-average ratio using only input modulated techniques.