Ultra-High Efficiency Microwave Rectifier Based on Patterned GaN Schottky Barrier Diode

In this paper, a microwave rectifier operating at 905 MHz is proposed based on a patterned GaN Schottky barrier diode (SBD). First, a heavily-doped and patterned GaN SBD demonstrates a low turn-on voltage of 0.38 V at 1mA, low series resistance of 1.5Ω, suitable zero-biased junction capacitance of 0.93 pF, and a breakdown voltage of 52 V, which is specially proposed for mid- and low-power microwave rectification around 905 MHz. Then by combining circuits techniques such as harmonic harvesting and impedance cancelation, a GaN based microwave rectifier that pursuing the highest efficiency is designed. The measurement shows that over 92% RF-DC conversion efficiency is achieved, while the high-efficiency power range(efficiency>80%) is extended to 16.5 dBm - 25 dBm, which indicate a great potential at the sensorial such as long-distance wireless power transmission and the internet of things.