Abstract
A novel bandpass filter (BPF) for an ultra-wideband (UWB) system is proposed in this letter. The BPF consists of four coplanar stripline (CPS)-to-microstrip transitions. Each transition is employed for broad electromagnetic (EM) coupling between a short-circuited CPS and an open-circuited microstrip line. The equivalent circuit model of the proposed geometry is derived and utilized in the impedance and mode matching analysis. Measured results show good agreement with the analysis and simulated ones.