Harmonically-tuned octave bandwidth 200 W GaN power amplifier

In this paper, the design, implementation, and experimental results of a 200 W high efficiency broadband GaN HEMT power amplifier (PA) are presented. Power combining was used to combine the outputs of two individual octave bandwidth 100 W power amplifiers. Optimum fundamental and harmonic load impedances were obtained using load-pull simulations for the active device across the design band. A systematic approach was applied for the design of wideband output and input matching networks. From continuous wave large-signal measurements a maximum output power of greater than 200 W was obtained over almost an octave bandwidth. The corresponding drain efficiency (power-added efficiency) ranged between 45-56% (40-52 %).