Miniaturized UWB Bandpass Filter with Dual Notch Bands and Wide Upper Stopband

In this paper, a miniature ultrawideband (UWB) bandpass filter with dual notch bands and wide upper stopband is presented. The ultrawide passband characteristic is achieved using a microstrip to slot line transition, and a wide upper stop band is realized using an elliptical lowpass filter. The dual band notches at 5.46 GHz and 8.04 GHz are obtained by incorporating defected microstrip structure in the input and output section. A prototype of the proposed UWB bandpass filter is fabricated and measured. The equivalent circuit of the proposed filter is also presented. A good agreement between the measured, EM simulated and circuit simulated responses is obtained.