Electrical Characteristics of Gated Anode Diodes Based on Normally Off Recessed‐Gate GaN High‐Electron‐Mobility Transistors for Rectenna Applications

Abstract

AlGaN/GaN high‐electron‐mobility transistor (HEMT)‐based gated‐anode diodes (GADs) for a 5.8 GHz rectenna application are proposed. An anode of the GAD is formed by connecting a gate and a drain of a normally off GaN HEMT. Herein, a wide recessed HEMT structure reported in the previous article is modified to a buried‐type recessed gate HEMT structure. The gate‐to‐cathode distance is optimized to maximize device performance. Typical direct current (DC) characteristics of the HEMTs are a threshold voltage (Vth) of +0.4 V and a maximum drain current (Imax) of 450 mA mm−1. GADs using the HEMTs show the characteristics of maximum forward current (If) of 600 mA mm−1 and reverse breakdown voltage (BVr) of more than 100 V. The GAD using the recessed gate structure HEMT is shown to significantly improve If and BVr simultaneously compared to the previous work using the wide recessed gate structure. The rectifying performance of a bridge‐type rectifier simulated with SPICE model of the GAD shows radio frequency (RF)–DC conversion efficiency of 84% and RF input power of 13 W at 5.8 GHz using four GADs with each gate width (Wg) of 400 μm.