An Efficient Linear Power Amplifier with 2nd Harmonic Injection

摘要

A 2.3GHz hybrid GaN power amplifier (PA) with 2^{nd harmonic injection (HI) in the output is studied in terms of efficiency and linearity enhancement under a two-tone signal input. The 2nd harmonic signal is obtained by frequency doubling of the main RF signal but with opposite phase for IMD₃ cancellation. The HI-PA demonstrates a peak drain efficiency of 80% (assuming 100% efficient 2 f₀ injection) at 14.1W output power and more than 10dB reduction in IMD₃ when the injected harmonic phase and amplitude are adjusted for a compromise between efficiency and linearity.}