Novel ultra-wideband (UWB) bandpass filter with a notched band using defected ground structure

A novel ultra-wideband (UWB) bandpass filter (BPF) with a notched band is presented, using a pair of triangle ring resonators with four open-stubs and defected ground structures (DGS). The double triangle ring resonators with four open-stubs which feed by a pair of interdigital coupled structure can obtain a UWB band with three modes. Then the medial circle ring DGS is added to create a notched band at 8.3 GHz to avoid Bande X signals. Moreover, the pairs of paracentral circular arc DGSs are used to create transmission zeros in upper stopband thus high modes are suppressed greatly. Another pairs of circular arc DGSs are used to improve the passband performance. Finally, simulated results show that the proposed BPF has a passband from 2.6 to 10.2 GHz and a wide stopband bandwidth with 20dB attenuation up to 21.3GHz.