Compact Complementary Symmetric Ring Resonator Band Stop Filter for Ku band applications

A band stop filter is proposed in this paper using a novel complementary symmetric ring resonator for Ku band applications. The designed filter consists of a microstrip transmission line with periodically loaded complementary symmetric ring resonator structures. Two adjacent rectangular symmetric ring resonators are used as complementary structures for the first time to design a bandstop filter. These structures have resulted in deep rejection in stopband and broad stopband. The bandstop filter is designed, simulated, and fabricated. The HFSS simulation, equivalent circuit simulation, and measured results are compared and observed with good similarity. The measured results have shown a 3 dB Fractional bandwidth of 12.4% over the center frequency 12.87GHz. The maximum attenuation obtained in the stopband is nearly 31dB.