Design and implementation of microwave dual-band bandpass filters using microstrip composite resonators

In this article, a novel type of dual-band bandpass filter (DBBPF) is proposed by using microstrip composite resonators, and its design method is developed based on the lumped-element equivalent circuit of the filter. Both the midband frequencies and the passband widths of the dual bands of the filter can be controlled separately. Four DBBPFs with different specifications are designed, fabricated, and tested, and the measured frequency responses agree favorably with theoretical predictions, validating sufficiently the proposed design theory and filter structures. (c) 2008 Wiley Periodicals, Inc.