Dual-Band Microstrip-Line BPFs Using Tap-Coupling Resonators

Abstract

We focus on various dual-band microstrip-line bandpass filters(BPFs) based on tap-coupled resonators. In this study, three types of the BPFs such as basic type, multiple poles based type and wide-band type are proposed and designed by classical filter theory based on narrow-band approximation method. These filters are analyzed by original computation programs and commercial circuit and electromagnetic simulators. And then, the proposed BPFs are fabricated and measured in our laboratory. From the results, we have confirmed that the proposed BPFs produce dual pass-band response, multiple attenuation poles and wide-passband characteristics. We also have observed very good agreements between the simulations and experiments.