Patent ID: 7511575

Claim:
A high-frequency power amplifier comprising: a transistor element having a plurality of unit transistors on a first semiconductor substrate, each of the unit transistors having a plurality of transistors connected in parallel with each other in multifinger form, and each of the unit transistors having a control terminal through which an input signal is input, a first terminal connected to a constant-potential end, and a second terminal through which an output signal is output; a high-frequency processing circuit having a plurality of first series resonance circuits shunt-connected between the control terminals of the unit transistors of the transistor element and the constant-potential ends, and located on a second semiconductor substrate; a first connection line connecting the plurality of control terminals of the transistor element to each other; a second connection line connecting the plurality of second terminals of the transistor element to each other; an input matching circuit connected to the first connection line; and an output matching circuit connected to the second connection line, wherein two of the first series resonance circuits have respective different resonance frequencies corresponding to second and higher harmonics of respective frequencies that are included in an operating frequency band of the transistor element.