An optimum ultra-wideband microstrip filter

An ultra-wideband (UWB) microstrip filter with a fractional bandwidth (FBW) of more than 100% is designed and demonstrated. This UWB microstrip-filter design is based on a circuit model for an optimum short-circuited stub transmission-line filter whose unit elements or connecting lines are nonredundant. A comparison study is carried out to show the advantages of this type of filter versus the conventional design, whose unit elements are redundant. The theoretical, simulated, and experimental results of the designed optimum UWB microstrip filter are presented. (c) 2005 Wiley Periodicals, Inc.