Lateral GaN Schottky Barrier Diode for Wireless High-power Transfer Application with High RF/DC Conversion Efficiency: From Circuit Construction and Device Technologies to System Demonstration

In this paper, we have carried out a comprehensive study on the wireless power transfer (WPT) concept from the rectifier circuit construction and state-of-art GaN Schottky Barrier Diode (SBD) device technology to the WPT system demonstration. Benefited from the wide bandgap, high mobility and saturation velocity of the GaN 2-dimensional-electron-gas (2DEG), engineered lateral GaN SBD with low turn-on voltage ( $\text{V}_{\text{on}}$ ) of 0.47 V, on-resistance ( $\text{R}_{\text{on}}$ ) of 4 Ω, breakdown voltage (BV) of 170 V and junction capacitance ( $\text{C}_{\text{j}}$ ) of 0.32 pF at 0 V bias are achieved, which satisfy the fundamental requirements for microwave power rectification. After incorporating the high performance GaN SBD into the optimized rectifier circuit, high RF/DC conversion efficiency of 79% is achieved and the input power of per single GaN SBD is increased by 10X when compared with that of a commercial available Si SBD at the same efficiency of 50% and frequency of 2.45 GHz. Based on the rectifier circuit, a microwave power transfer system is constructed with 400 LEDs lighted up, verifying the great promise of adopting high-power GaN SBD for the wireless high-power transfer as an alternative energy harvesting technique for future WPT application.