Novel Model Design of Compact Dual Notch-Bands of Attenuation for Bandpass Filters

In this paper, a new microstrip model design of bandpass filter is proposed. Open stubs are applied to the band pass filter to refine the skirt selectivity on both sides of the upper and lower fr equency band. Two attenuation poles are produced by this new structur e. The upper band pole is introduced by the hairpin-comb structure. The lower band pole is introduced by the tapped open stubs. We fabricated a new struc ture using milling machine at the Lab in University of North Texas (U NT). Two attenuation poles are realized at the upper band and the lower band respectively, one at 1.71GHz and one at 1.93GHz. Sharp roll-off on both sides of the pass band is obtained. Measured results show good selectivity at both upper and lower bands