Compact and highly selective right/left-handed loaded coplanar waveguide lines

A coplanar waveguide line based on a split ring resonator technology and loaded with metallic strips and/or series gaps is presented. Properties of such structures can be controlled by properly designing or adding loading elements. Wide shunt wires permit to control upper band rejection levels by means of an engineering of the electric plasma frequency. Also, the addition of series capacitances to previous unit cell implementations provides a transmission response almost symmetric while exhibiting a right-handed character along the pass band, contrary to conventional left-handed lines. In addition, a huge enhancement of the loaded Q quality factors, maintaining low insertion losses, is pointed out. The interpretation of the results is based on full-wave electromagnetic analysis and measured responses of different prototypes designed for microwave operation.