GaN HEMT-Based Pressure Sensor With Microwave Rectification-Enhanced Sensitivity

Abstract

This work presents a microwave rectification enhanced pressure sensor. The sensor consists of a 2.4-GHz GaN Schottky barrier diode (SBD)-based rectifier operating with a normally-off GaN high electron mobility transistor (HEMT) pressure sensor, forming a pressure sensing system by directly utilizing the HEMT as the rectifier’s load. The rectifier not only provides power to the sensor via RF-to-DC conversion but also improves the GaN HEMT’s pressure sensitivity through a positive feedback mechanism. Results show that its output voltage exhibits a significant response to pressure. The sensor achieves a sensitivity of 9.82 mV/kPa/V within the 0–170 kPa pressure range, which is 2.5 times that of traditional GaN HEMT pressure sensors.