Symmetrical frequency response in a split ring resonator based transmission line

A coplanar waveguide line based on a split ring resonator technology and loaded with metallic strips and capacitances is proposed. The addition of series capacitances to previous unit cell implementations dramatically improves the upper band rejection levels and provides a transmission response almost symmetric. The configuration also exhibits a band pass response with a right-handed character as a result of the balance between advance and delay phase offsets contrary to the conventional left-handed lines. The interpretation is based on an equivalent circuit model, full-wave electromagnetic analysis, and measured responses of a prototype designed for microwave operation.