Microstrip Bandstop Filters Based on Hexagonal Complementary Split Ring Resonators

Bandstop filters are realized by etching periodic patterns of complementary split ring resonators(CSRR) on the ground plane, exactly below the central microstrip transmission line. This article presents hexagonal CSRR in the design of a band bandstop filter with stopbands at 1.45GHz. First, a regular hexagonal shaped CSRR is used to realize a bandstop filter. This hexagonal shaped SRR is modified to a new structure to realize a bandstop filter with same resonant frequency. These two hexagonal CSRRs are found to have similar results and the modified hexagonal filter is compact compared to the regular hexagonal filter. The structure is simple and compatible with PCB technology. Simulation results of both structures are validated through measurements.