UWB bandpass filter with two notch-bands based on SCRLH resonator

A compact ultra-wideband (UWB) bandpass filter (BPF) with two sharply rejected notch-bands and wide stop-band is presented. The proposed UWB BPF is realised by cascading two interdigital hairpin resonator units, a coupled simplified composite right-left-handed (SCRLH) resonator, a semi-circle defected ground structure (S-DGS) and a semicircle stepped-impedance shunt stub (S-SISS). The SCRLH resonator is studied and employed to introduce two notched-bands. An S-DGS and an S-SISS are cascaded to suppress the spurious in the stop-band. Good insertion/return losses and high out-of-band rejections are achieved as demonstrated in both simulation and experiment.