A Compact Broadside Coupled Notched Band UWB Filter with Wide Upper Stopband

摘要

A broadside coupled ultra-wideband (UWB) bandpass filter (BPF) with notched band and wide upper stopband is proposed and implemented. Initially, a broadside coupled UWB filter structure with good passband characteristics is developed. To this, split ring resonator (SRR) metal lines of half guided waveguide length are coupled to generate passband notch. Later, stub lines are embedded in the input and output (I/O) feeding lines whose attenuation poles suppress the spurious harmonics and widen the stopband. Finally, the proposed structure is fabricated and measured which establishes the authenticity of the full-wave electromagnetic response. The passband extends from 2.85 to 11.3GHz with stopband of width 18GHz and depth greater than 18dB. The variation of group delay is less than 0.42ns in the passband. The proposed structure is small in size measuring 11.08x 11.7 mm(2).