A new narrow band microstrip patch filter for modern wireless applications

A narrowband, compact, and flexible fabricated microstrip bandpass filter design is introduced in this thesis as a candidate for use in modern wireless systems. The proposed filter design is based on the use of dual-mode (two pole) patch microstrip resonator with uniform geometrical slot. This filter has the advantages of possessing much narrower and sharper performance responses as compared to single mode resonator and other conventional square patch filters. The performance of filter structures, based on dual-mode resonators, has been evaluated using Microwave office electromagnetic software package. Dual slotted patch microstrip filters have been designed at resonant frequencies 4.16 and 2.04 GHz using a substrate with a dielectric constant of 10.8 and thickness of 1.27mm.Performance simulation results show that these filter structures offer very good frequency responses in addition to narrow bands gained, compactness properties and 2nd harmonic isolation in out of band region. Keywords: Microstrip Filter, Patch Bandpass Filter, Narrow Bandpass Filter