A high selectivity and wide stopband UWB bandpass filter using asymmetric SIRs with split‐end

Abstract

ABSTRACTIn this article, a design of high selectivity and wide stopband ultrawideband (UWB) filter based on the asymmetric step‐impedance resonator (SIR) with split‐end is proposed. By properly selecting the impedance ratio, R, and the length ratio, α, and arranging the length of split‐ends of the asymmetric SIR, the good UWB passband using only one asymmetric SIR is realized from 2.9 to 5.1 GHz. Moreover, by tuning the feedlines as I/O ports with the split‐ends of the asymmetric SIR, three transmission zeros are well investigated and introduced for improving the selectivity of passband and providing the spurious suppression. Measured results of the fabricated filter have a good agreement with the full‐wave simulated results. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:1353–1356, 2014