UWB BPF based on Interdigitated Coupled Lines with Short Ended Stubs and Asymmetrically loaded Stubs For Notch Implementation

In the following paper a miniature microstrip ultra-wideband (UWB) band pass filter (BPF) structure is introduced. The proposed filter is based on four interdigitated parallel coupled lines (which are quarter wavelength long at the mid-band frequency), short ended stubs and asymmetrically loaded stubs. The designed structure is compact and do have better selectivity at the resonant corner frequencies. Position of notched frequency can be varied at different desired frequencies by making adjustments to the width and length of asymmetrically loaded stubs. The proposed filter is designed at the center frequency of 6.5GHz and have a bandwidth of 8GHz. Designed structure attains Insertion Loss of 1.1 dB and Return Loss greater than 12 dB. The EM simulation of designed structure has been executed with the help full-wave simulator HFSS based on FEM method of simulation [8].