Theoretical analysis of matched impedance concentric square ring doubly negative material at microwave frequency

In this paper doubly negative (DNG) material using concentric square split ring resonator and wire on FR-4 substrate at microwave frequency is theoretically analyzed. Measurement and simulation analysis are carried out on CST microwave studio software to retrieve the transmission parameters. From transmission parameters, constitutive parameters like permittivity, permeability, refractive index, and impedance are obtained. Permittivity and permeability of DNG material is negative in the operating region of frequency. For the design, operating region lies in the range of 13.602 GHz to 13.980 GHz. At 13.878 GHz the design behaves as a matched impedance DNG material having impedance value of 314.189 Ω, which is close to impedance of air. Therefore, design gives systematic analysis for creating the matched impedance DNG material at higher frequency.