Microwave Ring Resonator Based Pressure Sensor

This paper demonstrates a microwave pressure sensor, which is based on microstrip line-fed ring resonators. The first ring resonator is loaded with the concentric cylindrical shafts, while the same number of the hollow shanks as the shafts are mounted on the second ring resonator. The arrangement of the cylindrical shaft and hollow shank allows for mechanical movement between two substrates while maintaining electrical contact. The external pressure applied to the substrate translates the cylindrical shaft into the hollow shank, resulting in a change in the resonant frequency. The proposed sensor is found to measure an applied pressure up to 40.5 kPa with an average sensitivity of 9.62 kHz/Pa.