Synthesis of Dual-Band Bandpass Filters with Asymmetric Stepped-Impedance CBACPW Resonators

A novel Dual-band bandpass filter (DBBPF) with an asymmetric topology and steppedimpedance Conductor-backed asymmetric coplanar waveguide (CBACPW) resonators is proposed in this paper. Compared with the existing DBBPFs with a same low-pass prototype, two additional transmission zeros are emerged by using the asymmetric topology. To facilitate the filter synthesis, design formulas of the filter are derived, and an ANN-based synthesis model of CBACPWs is developed. To validate the filter synthesis method, a DBBPF operating at GSM and GPS bands is designed, simulated and measured. A good agreement between simulation and measurement is obtained.