High-Power Wire Bonded GaN Rectifier for Wireless Power Transmission

A novel wire bonded GaN rectifier for high-power wireless power transfer (WPT) applications is proposed. The low breakdown voltage in silicon Schottky diodes limits the high-power operations of microwave rectifier. The proposed microwave rectifier consists of a high breakdown voltage GaN rectifying element for high-power operation and a novel low loss impedance matching technique for high efficiency performance. Wire bonding method is adopted to provide electrical connection between GaN chip and board which induces undesirable inductance. In order to realize high efficiency performance, an impedance matching network is proposed to exploit the unavoidable inductance along with a single shunt capacitor, resulting in a low loss matching circuit to achieve a compact high-power rectifier. The fabricated GaN rectifier exhibits a good performance in the high-power region and can withstand up to 39 dBm input power before reaching the breakdown limit at the operating frequency of 0.915 GHz and load resistance of 100Ω. It has a compact size and exhibits high efficiency performance in high-power region (achieved a maximum efficiency of 61.2% at 39 dBm), making it suitable for high-power applications like future unmanned intelligent devices and WPT in space applications.