Patent ID: 7646248

Claim:
A Doherty amplifier which comprises: a carrier amplifier for always performing a signal amplification operation regardless of a level of an input signal; a peaking amplifier for performing an amplification operation, starting from a high power output where a level of an input signal is equal to or greater than a predetermined level; an output combination circuit for combining and outputting outputs of the carrier amplifier and the peaking amplifier; and an input division circuit for dividing an input signal into the carrier amplifier and the peaking amplifier, wherein the Doherty amplifier includes a carrier amplifier output harmonic impedance tuning network which is installed at a rear end of the carrier amplifier so as to tune an output harmonic impedance of the carrier amplifier, wherein the carrier amplifier output harmonic impedance tuning network tunes a second output harmonic impedance to a near open circuit and a third output harmonic impedance to a near short circuit, and a peaking amplifier output harmonic impedance tuning network which is installed at a rear end of the peaking amplifier so as to tune an output harmonic impedance of the peaking amplifier.