volume | PIER Journals

Abstract

In this paper, a novel square-loop quad-mode resonator is presented. Due to its symmetry, the even-odd-mode method is utilized to analyze the resonant characteristics. Two modes resonating at lower frequencies are employed to construct the first passband, and other two form the second passband. Meanwhile, both passband center frequencies can be controlled by the corresponding physical dimensions. Two dual-band bandpass filters (BPFs) without and with source-load coupling operating at 2.4 and 3.5 GHz are designed based on the proposed quad-mode resonator. Due to the source-load coupling, the passband selectivity and band-to-band isolation of the latter one are better than those of the former one. For demonstration, these two filters are fabricated and measured, and the measured results show good agreement with the simulated ones.

1. Ruiz-Cruz, J. A., M. M. Fahmi, and R. R. Mansour, "Triple-conductor combine resonators for dual-band filters with enhanced guard-band selectivity," IEEE Trans. Microw. Theory Tech., Vol. 60, No. 12, 3969-3979, Dec. 2012. Google Scholar

2. Qin, W. and Q. Xue, "Complementary compact microstrip resonant cell and its applications to microwave single- and dual-band bandpass filters," IEEE Trans. Microw. Theory Tech., Vol. 61, No. 2, 1829-1838, Feb. 2013. Google Scholar

3. Naglich, E. J., J. Lee, H. H. Sigmarsson, D. Peroulis, and W. J. Chappell, "Intersecting parallel-plate waveguide loaded cavities for dual-mode and dual-band filters," IEEE Trans. Microw. Theory Tech., Vol. 61, No. 5, 1829-1838, May 2013. Google Scholar

4. Kuo, J.-T. and S.-W. Lai, "New dual-band bandpass filter with wide upper rejection band," Progress In Electromagnetics Research, Vol. 123, 371-384, 2012. Google Scholar

5. Kuo, J.-T., S.-C. Tang, and S.-H. Lin, "Quasi-elliptic function bandpass filter with upper stopband extension and high rejection level using cross-coupled stepped-impedance resonators," Progress In Electromagnetics Research, Vol. 114, 395-405, 2011. Google Scholar

6. Mondal, P. and M. K. Mandal, "Design of dual-band bandpass filters using stub-loaded open-loop resonators," IEEE Trans. Microw. Theory Tech., Vol. 56, No. 1, 150-155, Jan. 2008. Google Scholar

7. Zhang, X. Y., J.-X. Chen, Q. Xue, and S.-M. Li, "Dual-band bandpass filters using stub-loaded resonators," IEEE Microw. Wireless Compon. Lett., Vol. 17, No. 8, 583-585, Aug. 2007. Google Scholar

8. Wolff, I., "Microstrip bandpass filter using degenerate modes of a microstrip ring resonator," Electron. Lett., Vol. 8, No. 12, 302-303, Jun. 1972. Google Scholar

9. Hong, J. S. and M. J. Lancaster, "Bandpass characteristics of new dual-mode microstrip square loop resonators," Electron. Lett., Vol. 31, No. 11, 891-892, May 1995. Google Scholar

10. Hong, J. S. and H. Shaman, "Dual-mode microstrip open-loop resonators and filters," IEEE Trans. Microw. Theory Tech., Vol. 55, No. 8, 1764-1770, Aug. 2007. Google Scholar

11. Athukorala, L. and D. Budimir, "Compact dual-mode open loop microstrip resonators and filters," IEEE Microw. Wireless Compon. Lett., Vol. 19, No. 11, 698-700, Nov. 2009. Google Scholar

12. Sun, S.-J., B. Wu, T. Su, K. Deng, and C.-H. Liang, "Wideband dual-mode microstrip filter using short-ended resonators with centrally loaded inductive stub," IEEE Trans. Microw. Theory Tech., Vol. 60, No. 12, 3667-3673, Dec. 2012. Google Scholar

13. Sun, S.-J., S. Yang, B.Wu, K. Deng, and C.-H. Liang, "Dual-band bandpass filter using a single short-ended dual-mode resonator with adjustable first passband," Progress In Electromagnetics Research C, Vol. 37, 95-106, 2013. Google Scholar

14. Sun, S.-J., T. Su, K. Deng, B. Wu, and C.-H. Liang, "Shorted-ended stepped-impedance dual-resonance resonator and its application to bandpass filters," IEEE Trans. Microw. Theory Tech., Vol. 61, No. 9, 3209-3215, Sep. 2013. Google Scholar

15. Luo, S. and L. Zhu, "A novel dual-mode dual-band bandpass filter based on a single ring resonator," IEEE Microw. Wireless Compon. Lett., Vol. 19, No. 8, 497-499, Aug. 2009. Google Scholar

16. Sung, Y., "Dual-mode dual-band filter with band notch structures," IEEE Microw. Wireless Compon. Lett., Vol. 20, No. 2, 73-75, Feb. 2010. Google Scholar

17. Li, Y. C., H. Wong, and Q. Xue, "Dual-mode dual-band bandpass filter based on a stub-loaded patch resonator," IEEE Microw. Wireless Compon. Lett., Vol. 21, No. 10, 525-527, Oct. 2011. Google Scholar

18. Zhao, L.-P., X.-W. Dai, Z.-X. Chen, and C.-H. Liang, "Novel design of dual-mode dual-band bandpass filter with triangular resonators," Progress In Electromagnetics Research, Vol. 77, 417-424, 2007. Google Scholar

19. Chiou, Y.-C., P.-S. Yang, J.-T. Kuo, and C.-Y.Wu, "Transmission zero design graph for dual-mode dual-band filter with periodic stepped-impedance ring resonator," Progress In Electromagnetics Research, Vol. 108, 23-36, 2010. Google Scholar

20. Sun, S.-J., T. Su, K. Deng, B. Wu, and C.-H. Liang, "Compact microstrip dual-band bandpass filter using a novel stub-loaded quad-mode resonator," IEEE Microw. Wireless Compon. Lett., Vol. 23, No. 9, 465-467, Sep. 2013. Google Scholar

21. Gao, L. and X. Y. Zhang, "High-selectivity dual-band bandpss filter using a quad-mode resonator with source-load couopling," IEEE Microw. Wireless Compon. Lett., Vol. 23, No. 9, 474-476, Sep. 2013. Google Scholar

22. Cameron, R. J., "Advanced coupling matrix synthesis techniques for microwave filters," IEEE Trans. Microw. Theory Tech., Vol. 51, No. 1, 1-10, Jan. 2003. Google Scholar

Dr. Shou Jia Sun

Dr. Lei Lin

Prof. Bian Wu

Dr. Kun Deng

Professor Chang-Hong Liang