A novel dual-mode bandpass filter (BPF) using stub-loaded defected ground open-loop resonator is proposed in this article. Defected arrow-shaped stub is loaded to a defected ground open-loop resonator, and two non-degenerate modes are excited for dual-mode characteristics. Based on even- and odd-mode theory, dual-mode characteristics of the resonator is analysed. Design equations for the defected-ground resonator are investigated. A two-pole dual-mode bandpass filter operating at 2.4 GHz with fractional bandwidth of 7.97% is designed, fabricated, and measured. Good agreement between simulated and measured results verifies the validity of this design methodology.
2. Matsuo, M., H. Yabuki, and M. Makimoto, "Dual-mode stepped-impedance ring resonator for bandpass filter applications," IEEE Transactions on Microwave Theory and Techniques, Vol. 49, 1235-1240, 2001.
doi:10.1109/22.932241
3. Wang , Y. X. , B.-Z. Wang, J. P. Wang, and , "A compact square loop dual-mode bandpass filter with wide stop-band," Progress In Electromagnetics Research, Vol. 77, 67-73, 2007.
doi:10.2528/PIER07072707
4. Hong, J. S. and M. J. Lancaster, "Bandpass characteristics of new dual-mode microstrip square loop resonators," Electronics Letter, Vol. 31, No. 11, 891-892, 1995.
doi:10.1049/el:19950591
5. Chen , Y.-W., Y.-J. Liu, and M.-H Ho, "The quasi-elliptic bandpass ¯lter using quarter-wavelength Stepped Impedance Resonators," Progress In Electromagnetics Research Letters, Vol. 2, 605-608, 2006.
6. Chin, K.-S. and D.-J. Chen, "Novel microstrip bandpass filters using direct-coupled triangular stepped-impedance resonators for spurious suppression," Progress In Electromagnetics Research Letters, Vol. 12, 11-20, 2009.
doi:10.2528/PIERL09090602
7. Liu, , H. W., L. Shen, Z. C. Zhang, J. S. Lim, and D. Ahn, "Dual-mode dual-band bandpass filter using defected ground waveguide," Electronics Letter, Vol. 246, No. 13, 895-897, 2010.
doi:10.1049/el.2010.1034
8. Hong , J.-S. and H. Shaman, "Dual-mode microstrip open-loop resonators and filters," IEEE Transactions on Microwave Theory and Techniques, Vol. 55, No. 8, 2099-2109, 1996.
doi:10.1109/22.543968
9. Deng, H.-W. , Y.-J. Zhao, X.-S. Zhang, L. Zhang, and W. Zhao, "Compact dual-mode open stub-loaded resonator and BPF," Progress In Electromagnetics Research Letters, Vol. 14, 119-125, 2010.
doi:10.2528/PIERL10032904
10. Wang , L. and B.-R Guan, "Compact dual-mode DGS resonators and filters," Progress In Electromagnetics Research Letters, Vol. 25, 47-55, 2011.
Submit
