Design of Compact Hilbert Microstrip Bandpass Filter For Modern Wireless Communication Systems


This paper presents a new microwave narrow-band bandpass filter with aminiaturized size for use in modern wireless communication systems. Theproposed filter design topology is based on a single-mode microstrip resonatorconstructed in the form of Hilbert fractal geometries from 2nd to 4th iteration levels.The space-filling property the proposed filter topologies possess, has found toproduce reduced size structures corresponding to the successive iteration levels.Many filters have been designed for the Industrial Scientific Medical band (ISMband) applications at a design frequency of 2.4 GHz using a substrate with adielectric constant of 10.8 and thickness of 1.27mm. The performance of each ofthe resulting bandpass filter structures has been analyzed using a method ofmoments (MoM) based software package, Microwave Office 2007, fromAdvanced Wave Research Inc. Results show that these filters possess goodtransmission and return loss characteristics, besides the miniaturized sizes gained;making them the design specifications of most of wireless communication systems.