A New Narrow Band Dual-Mode Miniaturized Bandpass Filter Design for Wireless Communication Systems


A new narrowband, compact, and low profile microstrip filter design ispresented in this paper as a candidate for use in modern wireless systems. The proposed design is based on the use of fractal multiple ring resonator. Multiple ring resonators have advantages to possess much narrower and shaper performance responses than those of the single ring resonator. The proposed filter design is fractally generated using Minkowski-Like Pre-Fractal curve geometry applied to the conventional square microstrip square ring filter. Filter structures resulting from the successive iterations in the fractal generation process show aconsiderable size reduction compared with the conventional microstrip square ring filter designed at the same frequency using the same substrate material. The performance of the generated bandpass filter structures have been analyzed using method of moments (MoM) based software package Microwave Office 2007. Performance Simulation results show that filter structures employing 2nd and 3rd iterations offer size reduction percentages of about 61.5% and 77.7% respectivelyas compared with the conventional square ring filter