High-efficiency GaN/AlGaN HEMT oscillator operating at L-band

This paper presents a new design method to implement the high efficiency oscillator based on the AlGaN/GaN HEMT for the wireless power transmission (WPT) system. The oscillator has been developed with Se₂O₃-passivated AlGaN/GaN HEMT and has achieved the maximum efficiency of 40.5% and the maximum output power of 23 dBm for WPT applications. With both the high output power of the circuit and inherent device material advantages, the phase noise performances of -97 dBc/Hz and -125 dBc/Hz at offsets of 100 kHz and 1 MHz, respectively, have been achieved. To our knowledge, the achieved efficiency is the highest ever reported for a GaN oscillator.