Characterization of Conductor-Backed Dielectric Substrates Using a Novel Resonance-Based Method

A novel microwave resonance-based method is presented in this paper for complex permittivity characterization of conductor-backed materials. The proposed method constructs a nondestructive technique for extracting complex permittivity proprieties of thin conductor-backed dielectric substrates. The conductor-backed sample is integrated with a planar resonator by employing the conductor backing plane as a grounding surface to the resonance structure. The planar resonator is a finite circular conductive patch hosting a complementary split ring resonator (CSRR). The proposed method exhibits high sensitivity to the conductor-backed material measurements and characterization. Experimental validation of the numerical analysis of the proposed method is provided. Commonly used conductor-backed dielectric substrates with a wide range of relative permittivity values ranging from 2.2 to 10.2 were characterized using the proposed method. Compared to the state of the art material characterization methods using planar resonators, the presented method provides a nondestructive technique for complex permittivity characterization of thin conductor-backed dielectric substrates with high sensitivity to the dielectric properties.