Equivalent Circuit Analyzed of Complementary Split Ring Resonator DGS for Low Pass Filter

Abstract

This paper presents a novel complementary split-ring resonator (CSRR) defected ground structure (DGS) for low pass filter (LPF) design. The equivalent circuit (EC) model of the CSRR was extracted and discussed in details. Based on the advantages of the CSRR, a compact LPF was designed without open stubs. The 3-dB cut-off frequency of 4.89 GHz has presented good measured characteristics, including sharp selectivity, very low insertion loss of 0.695 dB and wide stopband from 5.02 GHz to 10 GHz below −32 dB. The LPF with low return loss and high out-band suppression is designed and fabricated effectively.