λ/4 stepped-impedance resonator bandpass filters fabricated on coplanar waveguide

Abstract

Simple and compact multi-stage microwave bandpass filters (BPFs) using /spl lambda//4 stepped-impedance resonators (SIRs) fabricated on coplanar waveguide (CPW) are presented, which are applicable for MMICs or high-T/sub c/ superconducting filters. An accurate, tuning-free, design method of the /spl lambda//4 SIR-BPF is demonstrated with assistance of full-wave electromagnetic field simulator, which is based on a conventional filter design method using impedance inverters. Full-wave simulation and experimental results for a two-stage Chebyshev BPF designed at 5 GHz agreed well with theoretical results.