A High Sensitivity Microwave Sensor for Dielectric Characterization of Substrates

A microwave sensor based on complementary multiple split-ring resonator (CMSRR) for substrates dielectric characterization is proposed in this paper. The microwave sensor is designed on Rogers RT/duroid 5880 substrate with a relative permittivity of 2.2. The proposed sensor is simulated and optimized to resonate at 8.51 GHz using High Frequency Structure Simulator (HFSS). At resonance, there is a very strong electric field across the CMSRR. By putting the substrates under test with relative permittivity ranges from 2.1-3 and constant dimensions 3.9 mm × 8.2 mm × 3 mm on the CMSRRs, the resonance frequencies of the device change obviously. The achieved sensitivity is up to 4.3%, making it a good candidate for dielectric characterization of material under test.