Stopband Characteristics for Periodic Patterns of CSRRs in the Ground Plane

Stop band filters are designed by etching periodic patterns of complementary split ring resonators (CSRRs) in the ground plane of a microstrip line. CSRRs, being sub-wavelength resonators, their size are much smaller than the conventional microstrip resonators. As a resonator, it has been observed that a single CSRR in the ground plane has a very high Q factor and gives a very low insertion loss in the stop band. It has also been observed that the period of the CSRR loaded microstrip line can be made as small as /10 of the operating wavelength thereby extensive size miniaturization is possible. With the increased number of CSRRs etching and decreased period of the periodic structure loaded with CSRRs in the ground plane of the microstrip line, the stop bandwidth increases and side by side the insertion loss level in the mid stop band frequency decreases significantly thereby further enhancing the stop band filter performance along with the extensive size miniaturization.