HIGH SELECTIVITY DUAL-WIDEBAND BANDPASS FILTER WITH TRIPLE-MODE STUB-LOADED STEPPED-IMPEDANCE RESONATORS

摘要

A novel high selectivity dual-wideband microstrip bandpass filter (BPF) with two triple-mode stub-loaded stepped- impedance resonators (SIRs) is proposed in this letter. Either of the SIRs can not only separately generate one passband but also control the passband performance. Because of the intrinsic characteristics of the SIRs, four transmission zeros can be generated to improve the selectivity. A dual-wideband filter with the fractional bandwidth 15.4% and 10.2% is designed and fabricated. The dual-wideband filter is evaluated by experiment and simulation with good agreement.