Metamaterial-Based Microstrip Soil Moisture Sensors

Abstract

In this paper a new low cost metamaterial-based soil moistures sensor is proposed. The designed sensors are based on resonant-type metamaterials. This metamaterial sensor consists of two asymmetric circular split ring resonators (aCSRRs) which exhibit high sensitivity quality factor and a thin microstrip line with 50 ohm characteristic impedance. The low cost FR4 dielectric board with relative permittivity 4.30 is used as substrate. The resonance frequencies of proposed sensor versus the soil moisture and its permittivity have been studied. It can be observed that higher effective permittivity is found when increase soil moister, this result will has an effect on a decreasing of the resonance frequency of the sensor. The sensors which using metamaterials may hope to fuel the revolution of sensing technology.