Microstrip Non-Foster Circuit High Efficiency High Power Class-J GaN HEMT Amplifier

摘要

This paper proposes Microstrip non-Foster circuit (NFC) enhanced high efficiency high power class-J GaN HEMT (gallium nitride high electron mobility transistor) amplifier. The NFC enhances the performance of the power amplifier (PA) by cancelling the power transistor's input parasitic capacitance. The PA was designed based on Cree's CGHV40030FP GaN HEMT biased with drain supply voltage of 50 V at quiescent drain-to-source current (IDS_q) of 15 mA. The NFC is part of the input matching network and contains two GaN HEMTs biased with drain supply voltage of 20 V at IDSq of 3 mA. The PA operates from 2.0 to 2.2 GHz. The NFC negative capacitance at 2.1GHz center frequency stood at -2.4 pF. The NFC PA has output power of 43.9 dBm (24.5 W), 69.3% drain efficiency, 66.4% power added efficiency (PAE) and transducer power gain of 11.9 dB.