摘要
A compact ultra-wideband (UWB) band-pass filter (BPF) with improved upper-stopband is proposed in this paper. The proposed UWB BPF is composed of two cascaded interdigital hairpin resonator units and two same semicircle defected ground structures (S-DGS). Interdigital hairpin resonator unit with different coupling and S-DGS with different dimensions are theoretically analyzed. The working frequency of the proposed UWB BPF is 3.1-10.6 GHz and upper-stopband with 15 dB attenuation is up to 18 GHz. Finally, measured results are presented, which are in good agreement with the simulation results.