Patent ID: 7411458

Claim:
Power amplifier (PA) apparatus comprising: a PA device operating at a fundamental frequency and having a maximum operating frequency that is higher than the fundamental frequency, an output current comprising a fundamental component at the fundamental frequency and a plurality of harmonic components at different harmonic frequencies of the fundamental frequency, and an output voltage based on the output current; a first matching circuit coupled to the PA device and corresponding to the fundamental component; and a second matching circuit coupled between the PA device and the first matching circuit and corresponding to a plurality of the harmonic components, wherein the second matching circuit comprises a plurality of matching portions operatively coupled together, with each matching potion corresponding to a different harmonic component of the output current, wherein the higher the harmonic frequency of the harmonic component, the closer its corresponding matching portion is coupled to the PA device, wherein the first and second matching circuits maintain the PA output voltage at a value that is no more than a predetermined maximum value, which is less than a breakdown voltage for the PA device.