GaN Schottky rectifier with Class-F harmonic termination for 10 GHz wireless power transfer

Abstract High-power rectification at X-band remains challenging because the diode must simultaneously offer a sufficiently high cutoff frequency and sustain large RF voltages. This work presents a 5.6-W, 10-GHz high-efficiency practical Class-F harmonic-terminated rectifier developed through device–circuit co-design. A custom finger-type GaN Schottky diode is fabricated, achieving a low zero-bias capacitance of 0.19 pF $0.19\,\text{pF}$ 0.19 pF , a breakdown voltage of 205 upper V $205\,\text{V}$ 205 V , a turn-on voltage of 1.24 upper V $1.24\,\text{V}$ 1.24 V , and a series resistance of 11 upper Omega $11\,\Omega$ 11 Ω , corresponding to a cutoff frequency of 76 GHz $76\,\text{GHz}$ 76 GHz . These characteristics enable fast switching and low parasitic losses suitable for high-power microwave rectification, and device reliability is confirmed through stable operation at 350 upper K $350\,\text{K}$ 350 K and a 24-h stress test. Leveraging this diode, the rectifier is optimized with a harmonic-termination network to realize the intended Class-F boundary conditions through controlled second- and third-harmonic impedances. Measurements show a peak RF-to-DC efficiency of 62.1 percent sign $62.1\%$ 62.1 % at an input power of