Modeling and simulation of novel ultra-narrowband miniature microstrip filters for mobile and wireless critical applications

Novel ultra-narrowband microstrip filter structures of miniature size are modeled, designed, and simulated. Network and fullwave EM Sonnet simulators are used. The best proposed filters have a significant improvement in narrowband performance (up to nine times at mobile frequencies and 2 7 times at wireless frequencies), sharp selectivity, and extremely compact size. The geometry shows a crucial effect on the fractional bandwidth (FBW) rather than the spacing between resonators only. 2005 Wiley Periodicals, Inc.