Patent ID: 7315207

Claim:
A Doherty amplifier having: a carrier amplifier which is performing a signal amplifying operation at all times irrespective of an input signal level; a peak amplifier which performs an amplifying operation only when the input signal level increases to a certain level or higher to generate high power; an output combiner circuit for combining the outputs of said carrier amplifier and said peak amplifier to deliver a combined output; and an input branching circuit for distributing an input signal to said carrier amplifier and to said peak amplifier, said Doherty amplifier characterized by comprising: a first pre-distortion compensation circuit disposed at a stage previous to said carrier amplifier and having such characteristics that compensate said carrier amplifier for a distortion characteristically produced on the operation of said carrier amplifier; and a second pre-distortion compensation circuit disposed at a stage previous to said peak amplifier and having such characteristics that compensate said peak amplifier for a distortion characteristically produced on the operation of said peak amplifier.