Design of a Dual-Wideband BPF with Parallel-Coupled Stepped Impedance Resonator and Open-Circuited Stubs

Abstract

This brief paper proposes a dual-wideband filter consisting of a parallel-coupled stepped-impedance-resonator (SIR) and open-circuited stubs. Firstly, a notched UWB (ultra-wideband) bandpass filter (BPF) with steep skirt characteristics is theoretically designed. Then a bandstop filter(BSF) is implemented using an SIR and open stubs. By replacing the transmission line part of UWB filter with the BSF, a novel dual-wideband filter (DWBPF) is realized. As a design example, a DWBPF with two passbands, i.e. 3.4-4.8GHz and 7.25-10.25GHz, is designed to validate the design procedure. The designed filter exhibits steep skirt characteristics.