A FURTHER INVESTIGATION ON THE PERFORMANCE OF THE BROADSIDE COUPLED RECTANGULAR SPLIT RING RESONATORS

In this paper, a numerical study based on the Finite Element Method (FEM) formulation of Ansoft's High Frequency Structure Simulator (HFSS) is reported to investigate the performance of a conformal Broadside Coupled Rectangular Split Ring Resonators (BC-SRR) of negative effective permeability around a resonant frequency of 1.27 GHz for non-linear polarization applications. The size of the BC-SRR is 15 mm x 15 mm x 0.8 mm on a polyimide substrate with a relative permittivity of 3.5 and a loss tangent of 0.004. The performance of the BC-SRR is characterized in terms of reflection and transmission spectra, effective relative permittivity and permeability, and the dispersion diagram for both flat and twisted profiles. The flat BC-SRR operates over the frequency range from 1.2615 to 1.2842 GHz. The twisted BC-SRR inclusions are investigated at 90 degrees. It has been found that the resonant frequency is changed to 1.1064 GHz and bandwidth becomes from 1.08 GHz to 1.0537 GHz for the twisted profile. Moreover, it is found that the unit cell of the twisted BC-SRR profile is based on two BC-SRRs inclusions. Furthermore, it is found that the twisted profile exhibits negative relative permittivity and permeability simultaneously.