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.

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.

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.

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Dr. Shou Jia Sun

Dr. Lei Lin

Prof. Bian Wu

Dr. Kun Deng

Professor Chang-Hong Liang