Co-design of GaN based Schottky Barrier Diode and Rectification Sensor with High Efficiency and Sensitivity

In this paper, a quasi-vertical GaN-SBD and a rectification sensor are specially co-designed for wireless IOT application, i.e., long distance wireless power transmission and pressure sensing. Solutions including semiconductor devices, rectification circuits, and sensing mechanisms are discussed. First, a quasi-vertical GaN-SBD that specially optimized for 928 MHz rectification is proposed, with an especially enlarged junction capacitance of 0.845 pF, reduced series resistance of 1.81 Omega, and suitable breakdown voltage of 35 V. Second, a single SBD based rectifier is designed and measured, with a power capacity over 31 dBm and a rectification efficiency better than 85%. Last, a low cost and low complexity rectification pressure sensor is designed by coupling the rectifier and a piezo-permittivity liquid metal elastomer foam, without introducing any extra pressure detection circuit. Experiments show that the prototype can send an audible and visual alarm to indicate a pressure loss, over a remote operation distance ranging from 0.1 to 3 meters.