In this paper, a new dual-band bandpass filter (BPF) using a cross ring resonator is designed. The cross ring resonator is modified from a typical dual-mode ring resonator and has four parallel coupling gaps (g). The resonant modes of the proposed cross ring resonator is investigated first. It is found that the first mode and the second mode can be tuned individually. The filter performances are simulated by using full-wave simulator IE3D. A filter example having two passbands operated at 2.4/5.2 GHz of wireless local area network (WLAN) applications is described to verify the design concept. The fabricated filter has measured characteristics including average insertion losses of 2.0 dB and 1.8 dB and return losses larger than 22 dB and 10 dB for 2.4/5.2 GHz, respectively. Two transmission zeros with high frequency selectivity of 40 dB and 42 dB are obtained near the first passband at 2.2 GHz and 2.7 GHz, respectively. This design is very simple as compared to other design methods, and the measured results prove the design concept of the proposed structure.
2. Weng, M.-H., S.-K. Liu, H.-W. Wu, and C.-H. Hung, "A dual-band bandpass filter having wide and narrow bands simultaneously using multilayered stepped impedance resonators," Progress In Electromagnetics Research Letters, Vol. 13, 139-147, 2010.
doi:10.2528/PIERL10022401
3. Chang, C. H., H. S. Wu, J. Yang, and C. K. C. Tzuang, "Coalesced single-input single-output dual-band filter," IEEE MTT-S International, Vol. 1, 511-514, Jun. 2003.
4. Chang, S. F., Y. H. Jeng, and J. L. Chen, "Dual-band step-impedance bandpass filter for multimode wireless LANs," Electronics Letters, Vol. 50, No. 7, 38-39, Jul. 2004.
5. Weng, M. H., C. Y. Hung, and W. N. Chen, "Dual-mode bandpass filters using triangle ring resonators with coupling stubs," Microw. & Opt. Tech. Lett., Vol. 43, No. 6, 512-515, Dec. 2004.
doi:10.1002/mop.20519
6. Huang, T.-H., H.-J. Chen, C.-S. Chang, L.-S. Chena, Y.-H. Wang, and M.-P. Houng, "A novel compact ring dual-mode filter with adjustable second-passband for dual-band applications," IEEE Microw. Wireless Compon. Lett., Vol. 16, No. 6, 360-362, Jun. 2006.
doi:10.1109/LMWC.2006.875607
7. Weng, M. H., C. Y. Hung, and H. W. Wu, "A novel dual-band bandpass filter using dual-mode resonators," IEICE Electric Lett., Vol. E88-C, No. 1, 146-148, Jan. 2005.
doi:10.1093/ietele/E88-C.1.146
8. Chen, J.-X., T. Y. Yum, J.-L. Li, and Q. Xue, "Dual-mode dual-band bandpass filter using stacked-loop structure," IEEE Microw. Wirel. Compon. Lett., Vol. 16, No. 9, 502-504, Sep. 2006.
doi:10.1109/LMWC.2006.880705
9. Zhang, X. Y. and Q. Xue, "Novel dual-mode dual-band filters using coplanar-waveguide-fed ring resonators," IEEE Trans. Microw. Theory Tech., Vol. 55, No. 10, 2183-2190, Oct. 2007.
doi:10.1109/TMTT.2007.906501
10. Liu, H., B. Ren, X. Guan, J. Lei, and S. Li, "Compact dual-band bandpass filter using quadruple-mode square ring loaded resonator (SRLR)," IEEE Microw. Wireless Compon. Lett., Vol. 23, No. 4, 181-183, Apr. 2013.
doi:10.1109/LMWC.2013.2247749
11. Ren, B., H. Liu, Z. Mai, M. Ohira, P. Wen, X. L. Wang, and X. Guan, "Compact dual-band differential bandpass filter using quadruple-mode stepped-impedance square ring loaded resonators," IEEE Access, Vol. 6, No. 9, 21850-21858, Sep. 2018.
doi:10.1109/ACCESS.2018.2829025
12. IE3D Simulator, Zeland Software, Inc., , 2002.
Submit
