Compact UWB Bandpass Filter Based on Signal Interference Techniques

This letter presents a new type of compact ultra-wideband (UWB) bandpass filter (BPF) based on interference techniques. The structure is formed by a short-ended coupled line coupler connected in parallel to a transmission line. The transmission and reflection zeros of the filter can be controlled through the analytical equations and rules given. To validate the suggested filter scheme, the design, fabrication and measurement of a microstrip UWB BPF is presented.