Incorporation of Square-shaped Complimentary Split Ring Resonator for Characteristics Enhancement of SIW-based Bandpass Filter

In this paper, incorporation of square-shaped complimentary split ring resonator (CSRR) for enhancing the characteristics of substrate integrated waveguide (SIW)-based bandpass filter (BPF) is investigated. The investigation is focused on how the amount of CSRR determines the characteristics of filter, such as bandwidth, insertion loss, and return loss. The enhancement is applied for an SIW-based BPF without CSRR and with a particular number of CSRRs. The proposed SIW-based BPF is designed on a Flame Retardant (FR) 4 epoxy dielectric substrate with the dimensions of 63 mm × 43 mm and the thickness of 1.6 mm to work at the center of frequency 2.4 GHz. The characterization results show that proposed SIW-based BPF with squared-shaped CSRR has the –3dB working bandwidth and the fractional bandwidth of 1.28 GHz (1.86 GHz – 3.16 GHz) and 251%, respectively, while the value of S11 is –17.191 dB at the frequency of 2.4 GHz. The results demonstrate a good applicability of proposed SIW-based BPF which are comparable to the simulated ones.