A Novel Metamaterial Based Microstrip Sensor for Ultrasensitive Humidity Monitoring

This paper presents a novel, highly sensitive metamaterial-based microstrip sensor for ultrasensitive humidity monitoring. The proposed microstrip sensor consists of a flared microstrip line that is loaded with two complementary split ring resonators (CSRR) coupled by two arms. This microstrip sensor uses Kapton 500 HN as a substrate, whose permittivity alters with the relative humidity (RH) of the environment. Further, the proposed sensor is designed to resonate at 15.7 GHz with a sensitivity of 14.81 MHz/% RH across the relative humidity (RH) of 10-90 %. The parameters of the proposed microwave sensor are optimized using the CST-microwave studio software. The simulation results show that the suggested sensor can be used for applications requiring extremely sensitive humidity monitoring.