Title :
Compact wide-stopband microstrip bandpass filterbased on stub-loaded stepped-impedance resonators
Author :
Wu, S.-R. ; Hsu, Ko-Wen ; Tu, Wen-Hua
Author_Institution :
Dept. of Electr. Eng., Nat. Central Univ., Jhongli, Taiwan
Abstract :
This study presents compact wide-stopband microstrip bandpass filters using stub-loaded stepped-impedance resonators. The resonators consist of three stepped-impedance sections. By adjusting the parameters of the resonators, one can control the frequencies of the resonant modes as well as the frequency of the transmission zero. When the transmission zero frequency is close to the spurious resonant mode frequencies, one can have a wide-stopband bandpass filter without external filtering circuits or increasing the resonator number for suppressing the spurious passbands. To validate the design concept, three dual-band bandpass filters and one wideband bandpass filter are designed, fabricated and tested.
Keywords :
band-pass filters; band-stop filters; optical design techniques; optical fabrication; optical filters; optical resonators; dual-band bandpass filters; external filtering circuits; one wideband bandpass filter; stub-loaded stepped-impedance resonators; transmission zero frequency; wide-stopband bandpass filter; wide-stopband microstrip bandpass filter;
Journal_Title :
Microwaves, Antennas & Propagation, IET
DOI :
10.1049/iet-map.2012.0257