volume | PIER Journals

Abstract

A novel, compact wideband bandpass filter based on an improved quad-mode resonator is proposed in this paper. Due to the usage of a coupled-line section, the resonator has a quad-mode behavior. The resonant frequencies can be tuned by regulating not only the electrical lengths, but also the characteristic impedances. Owing to the symmetry of the construction, even- and odd-mode analysis is utilized to analyze the proposed resonator. Finally, a wideband bandpass filter with 88% (2.1 to 5.4 GHz) relative bandwidth is designed, fabricated, and measured. The measured results are in good agreement with the simulated ones, which demonstrates the feasibility of the design approach.

1. Li, X. P. and X. Ji, "Novel compact UWB bandpass filers design with cross-coupling between λ/4 short-circuited stubs," IEEE Microw. Wireless Compon. Lett., Vol. 24, No. 1, 23-25, Jan. 2014.
doi:10.1109/LMWC.2013.2287231

2. Zhang, R. Q. and L. Zhu, "Design of a wideband bandpass filter with composite short- and open-circuited stubs," IEEE Microw. Wireless Compon. Lett., Vol. 24, No. 2, 96-98, Feb. 2014.
doi:10.1109/LMWC.2013.2291197

3. Jankovic, N. and V. Crnojevic-Bengin, "A compact wideband filter based on a grounded transversal resonator," IEEE Int. Conf. on Microw. Communications Antennas and Electronic Systems, 1-5, Tel Aviv, Israel, Oct. 2013.

4. Gao, L., X. Y. Zhang, B.-J. Hu, and Q. Xue, "Novel multi-stub loaded resonators and their applications to various bandpass filters," IEEE Trans. Microw. Theory Tech.,, Vol. 62, No. 5, 1162-1172, May 2014.
doi:10.1109/TMTT.2014.2314680

5. Xu, J., W. Wu, and C. Miao, "Compact and sharp skirts microstrip dual-mode dual-band bandpass filter using a single quadruple-mode resonator (QMR)," IEEE Trans. Microw. Theory Tech., Vol. 61, No. 3, 1104-1113, Mar. 2013.
doi:10.1109/TMTT.2013.2238949

6. Feng, W. J., W. Q. Che, Y. M. Chang, S. Y. Shi, and Q. Xue, "High selectivity fifth-order wideband bandpass filters with multiple transmission zeros based on transversal signal-interaction concepts," IEEE Trans. Microw. Theory Tech., Vol. 61, No. 1, 89-97, Jan. 2013.
doi:10.1109/TMTT.2012.2227785

7. Zhu, L., S. Sun, and R. Li, Microwave Bandpass Filters for Wideband Communications, Chapters 4 and 5, Wiley, New Jersey, USA, 2012.
doi:10.1002/9781118197981

8. Zhu, L., S. Sun, and W. Menzel, "Ultra-wideband (UWB) bandpass filters using multiple-mode resonator," IEEE Microw. Wireless Compon. Lett., Vol. 15, No. 11, 796-798, Nov. 2005.

9. Wang, H., Q.-X. Chu, and J.-Q. Gong, "A compact wideband microstrip filter using folded multiple-mode resonator," IEEE Microw. Wireless Compon. Lett., Vol. 19, No. 5, 287-289, May 2009.
doi:10.1109/LMWC.2009.2017591

10. Nosrati, M. and M. Mirzaee, "Compact wideband microstrip bandpass filter using quasi-spiral loaded multiple-mode resonator," IEEE Microw. Wireless Compon. Lett., Vol. 20, No. 11, 607-609, Nov. 2010.
doi:10.1109/LMWC.2010.2068570

11. Li, J., S.-S. Huang, and J. Z. Zhao, "Compact dual-wideband bandpass filter using a novel penta-mode resonator (PMR)," IEEE Microw. Wireless Compon. Lett., Vol. 24, 668-670, 2014.
doi:10.1109/LMWC.2014.2341014

12. Li, G. and X.-Y. Zhang, "High-selectivity dual-band bandpass filter using a quad-mode resonator with source-load coupling," IEEE Microw. Wireless Compon. Lett., Vol. 23, No. 9, 474-476, Sep. 2013.
doi:10.1109/LMWC.2013.2274995

13. 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.
doi:10.1109/LMWC.2013.2274038

14. Chen, F. C., Q. X. Chu, Z. H. Li, and X. H. Wu, "Compact dual-band bandpass filter with controllable bandwidths using stub-loaded multiple-mode resonator," IET Proc. Microw., Antennas Propag., Vol. 6, No. 10, 1172-1178, 2012.
doi:10.1049/iet-map.2011.0523

15. Zhang, S. and L. Zhu, "Compact and high-selectivity microstrip bandpass filters using triple-/quad-mode stub-loaded resonators," IEEE Microw. Wireless Compon. Lett., Vol. 21, No. 10, 522-524, Oct. 2011.
doi:10.1109/LMWC.2011.2166252

16. Kim, C.-H. and K. Chang, "Independently controllable dual-band bandpass filters using asymmetric stepped-impedance resonators," IEEE Trans. Microw. Theory Tech., Vol. 59, No. 12, 3037-3047, Dec. 2011.
doi:10.1109/TMTT.2011.2168973

17. Song, K. and Q. Xue, "Novel broadband bandpass filters using Y-shaped dual-mode microstrip resonators," IEEE Microw. Wireless Compon. Lett., Vol. 19, No. 9, 548-550, Sep. 2009.
doi:10.1109/LMWC.2009.2027058

18. Song, K. and Q. Xue, "Inductance-loaded Y-shaped resonators and their applications to filters," IEEE Trans. Microw. Theory Tech., Vol. 58, No. 4, 978-984, Apr. 2010.
doi:10.1109/TMTT.2010.2042509

19. Duong, T. H. and I. S. Kim, "Steeply sloped UWB bandpass filter based on stub-loaded resonator," IEEE Microw. Wireless Compon. Lett., Vol. 20, No. 8, 441-443, Aug. 2010.
doi:10.1109/LMWC.2010.2049480

20. Salleh, M. K. M., G. Prigent, O. Pigaglio, and R. Crampagne, "Quarter-wavelength side-coupled ring resonator for bandpass filters," IEEE Trans. Microw. Theory Tech., Vol. 56, No. 1, 156-162, Jan. 2008.
doi:10.1109/TMTT.2007.912167

Dr. Lixia Nan

Prof. Yongle Wu

Dr. Weimin Wang

Dr. Shulan Li

Dr. Yuan'an Liu