Input–output waveform engineered inverse Class F power amplifiers with high efficiency

This paper studies the influence of the gate voltage of the power amplifier (PA) on the drain current and efficiency. This study proposes a theory of controlling input non‐linearity to improve the efficiency of PAs. The theoretical efficiency of the inverse Class F PA that controls the input nonlinearity is within the range of 77% to 97%. A new design method for the inverse Class F PA reconstructs the design of the load admittance space into a region instead of a point. To verify the validity of the proposed theory, an inverse Class F PA is designed and fabricated using a commercial 10 W GaN high electron mobility transistor (HEMT). Results of the measurement show a high drain efficiency (DE) of 78.5%, an output power of 41.6 dBm, and a large signal gain of 12.1 dB at 1.5 GHz. The overall PA's size is controlled at 80*50 .