UWB bandpass SSL filter with an adjustable notched band and four transmission zeros

UWB suspended stripline (SSL) bandpass filter with an adjustable notched band and four transmission zeros (Tzs) is proposed here. To prevent interference signals from the wireless local-area network (WLAN) entering UWB system, a short-stub resonant network is introduced to this UWB filter. In addition, utilizing different resonant modes of the two short-stubs, four Tzs are generated to improve the skirt selectivity. Both the centre frequency of the notched band and the positions of Tzs can be controlled by tuning the structural parameters. The UWB SSL bandpass filter is designed, fabricated and tested. The measured results are in good agreement with the simulated results.