Ultra-wideband bandpass filter with a notch band using EBG array etched ground

A novel ultra-wideband (UWB) bandpass filter (BPF) with a notch band is proposed and implemented. The filter is realized by using a high pass filter (HPF) and an array of multiband electromagnetic bandgap (EBG) cells etched on the ground of a 50 Ω microstrip line. The first and third stopband of the designed EBG array generate the edges at each side of the passband of the UWB BPF, while the second stopband creates a very sharp notch response. Since it is the passband of the designed EBG array at lower frequency, a HPF is involved. To the authors' knowledge, we present for the first time a sharp notch band generated by using an EBG array in UWB BPF. The proposed filter was successfully designed, simulated and fabricated. The measured results show that the proposed BPF has a wide bandwidth from 3.8 GHz to 10.1 GHz with a notch response centered at 5.1 GHz. Both simulated and measured results are described. © 2011 VSP.