In this letter, a novel dual-mode bandpass filter (BPF) using stepped impedance resonators (SIRs) for simultaneous low insertion-loss and wide passband has been designed. This novel wideband dual-mode BPF is formed by a microstrip square ring resonator with direct-connected orthogonal feed lines, and two impedance steps as perturbations. By varying the impedance ratio (K) of the SIRs, the wideband bandwidth can be tuned with more freedoms. The design procedure using the analysis of even and odd mode is described in this paper. The wideband BPF with relative bandwidth of 76.5% is simulated using the full wave electromagnetic simulation, and then fabricated and measured using the network analyzer.
Relation:
Microwave and Optical Technology Letters ,Vol.50 no.4, pp.1104-1107
