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

, 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

37.5 dBm $37.5\,\text{dBm}$ 37.5 dBm

with a

470 upper Omega $470\,\Omega$ 470 Ω

load. Rather than pursuing a single absolute performance metric, the core contribution lies in demonstrating a device–circuit co-design methodology. By integrating targeted device optimization with harmonic-termination circuit design, this approach addresses combined challenges of frequency and power scaling in high-power X-band microwave rectification.