Ultra-wideband bandpass filter with notched band using microstrip/CPW structure

In this paper, a new ultra-wideband (UWB) bandpass filter (BPF) with narrow notched (rejection) band in the UWB passband, which is realized with hybrid microstrip/CPW structure, is presented and implemented for using in wireless communication applications within the unlicensed UWB range set by the Federal Communications Commission (FCC). Such an UWB bandpass filter with notched band is required in practical systems in order to avoid the interference between the UWB radio system and existing radio systems. The notched band can be easily adjusted to some specific frequency band by tuning the length of the embedding open stub on the bottom of the coplanar waveguide (CPW). The UWB bandpass filters with notched band have been carried out by related simulations and designs. The filters proposed have demonstrated relative excellent ultra-wide bandwidths and notched band performances compared with the references.