An ultra-wideband bandpass filter using EBG structure

The design and modeling of a compact microwave ultra-wideband bandpass filter (BPF) are presented, by cascading three coplanar-waveguide (CPW) resonators. Electromagnetic band gap (EBG) structures are utilized in the proposal design to pursue good RF performances. The BPF is operated from 13.5 to 25 GHz with good stop rejection and sharp roll-off frequency. Its stop rejection levels are -20 dB in both the lower and upper stop-band.