Modeling and Validation of Coplanar Waveguide Elliptic Filter Using Square Open Complementary Split-Ring Resonator

Abstract In this article, an elliptic low-pass filter is implemented in coplanar waveguide technology by etching an open complementary split-ring resonator and one open split-ring slot in the central transmission strip. The structures behave as series-connected parallel resonant tanks, whereas metallic patches etched in the back side of the substrate provide the required shunt capacitances to achieve the elliptic function response. An order-5 elliptic low-pass filter has been designed to illustrate the possibilities of this new approach. Since the open complementary split-ring resonator is an electrically small resonator and the dimension of the open split-ring slot is also very small, the designed filter dimensions are also small compared to the filters designed by split-ring resonators, complementary split-ring resonators, or other procedures.