Development of microstrip BPF using open split ring resonator with square groundplane window

This paper presents the development of microstrip bandpass filter (BPF) using open split ring resonator (OSRR) incorporated with square groundplane window. The microstrip BPF is comprised of 2 pairs of 3 cascaded OSRR connected with microstrip lines. Here, the incorporation of square groundplane window underneath the OSRR is applied to improve the passband bandwidth response of proposed BPF. In the design process, some parametrical study is performed to optimize the BPF in achieving the optimum bandwidth response. The proposed microstrip BPF is then realized on a 0.8mm thick FR4 Epoxy dielectric substrate with the dimension of 35mm × 60mm. The measurement result shows that realized microstrip BPF has the bandwidth response of 1.12GHz ranges from 1.50GHz to 2.62GHz which is comparable with the design result.