A compact UWB bandpass filter using two-section open-circuited stubs to realize transmission zeros

A design of a compact ultra-wideband (UWB) bandpass filter is presented in this paper. The filter is synthesized by a modified theory using Z-transform technique. In order to get sharp attenuations of the filter, shunt two-section open-circuited stubs are employed to produce transmission zeros in the lower and upper stopbans. A 3-degree UWB filter is designed and implemented in the form of microstrip lines, and the measured characteristics show good agreement with the theoretical and simulated results.