Very high efficiency microwave amplifier. The harmonic manipulation approach

The harmonic manipulation approach represents the best solution to improve power amplifier performance. Remarkable improvements in terms of output power, power gain and power added efficiency is demonstrated, suggesting different solutions, which represent a trade off between achievable performances and circuit complexity. While explaining some of the contradictory results already reported in the literature and giving a physical insight to the harmonic manipulation mechanism, the proposed approach suggests some useful guidelines for the microwave amplifier design. Finally, experimental results obtained at 5 GHz and 20 GHz confirm the feasibility of the proposed approach, both in the microwave and millimetre wave range