Design of UWB bandpass filter with embedded open-circuited stub multi-mode resonator

A compact microstrip ultra-wideband (UWB) bandpass filter (BPF) with a narrow notched band in the passband is presented in this letter. To achieve a notched band, an embedded open-circuited stub multi-mode resonator is utilized in the filter design. The bandwidth of the notched filter can be controlled by adjusting the width of the stub. The length of the stub can be tuned to select a specific frequency for the notched band. Predicted frequency responses are verified by the simulation and measurement.