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.