<p>A high efficiency power amplifier of the present invention includes a transistor and an output power processing circuit section. The output power processing circuit section includes an output matching circuit section and an output harmonic processing circuit section. The output matching circuit section carries out impedance matching to the fundamental wave component of the output power. The output harmonic processing circuit section carries out a reactive power control to a reactive power of a plurality of harmonic power components respectively having a plurality of harmonic angular frequencies which are integral multiples of the base angular frequency of the output power. The output harmonic processing circuit section is formed to realize the reactive power control to at least one of the plurality of harmonic power components by orthogonalizing the phases of the current and voltage in the reactive power.</p>
