A dual-band bandpass filter using dual and triple-mode resonators

A compact microstrip dual-band bandpass filter with a controllable bandwidth for each passband is presented in this paper. Each passband is independently designed using two different dual and triple-mode resonators. The proposed dual-band bandpass filter has five transmission zeros. Two transmission zeros are generated by each dual-mode resonator. An additional transmission zero is generated through input/output port coupling. The dual-band bandpass filter application is designed for a 2.4/5 GHz WLAN. Experimental measurements are presented in order to validate the theory.