Design of UWB bandpass filter with dual notched bands using E-shaped resonator

A new microstrip ultra-wideband (UWB) bandpass filter (BPF) with dual notched bands based on E-shaped resonator is proposed in this paper. The basic UWB BPF is composed of microstrip lines and rectangular patch mutiple-mode resonator (MMR). To achieve dual notched bands, the proposed UWB BPF used E-shaped resonator coupled to the main transmission line of the basic UWB BPF. The filter has passband from 2.9 GHz to 10.6 GHz, the first notched band is designed from 3.5 to 3.9GHz and the second notched band is designed from 6.7 to 7.3GHz, both of which have less than 0.8 dB magnitude of insertion loss and greater than 20dB return loss. The simulation results show that the proposed filter has good wideband filtering performance with sharp rejection skirts outside the passband.