volume | PIER Journals

Abstract

In this paper, two kinds of dual-band bandpass filter (BPF) based on a single square ring resonator are presented, which are realized by loading capacitance or inductive stubs, respectively. Even-odd-mode analysis is applied to explain their model characteristics. One filter is implemented by loading a pair of capacitance stubs, and both in-band couplings can be tuned in a reasonable range. Another filter is completed by loading a pair of inductive stubs, and the first and second passband center frequencies can be controlled independently. For demonstration, two filters operating at 2.45/5.25 GHz and 2.4/5.25 GHz are designed and fabricated. The simulated and measured results show good agreements.

1. Xu, F., Z.-J.Wang, M. Xiao, J.-Z. Duan, J.-Y. Cui, Z. Zhu, M. Ju, and Y. Liu, "A compact dual-band band-pass filter with wide stop-band using two resonators combined by via-hole," Progress In Electromagnetics Research C, Vol. 41, 81-95, 2013.

2. Jia, D.-H., Q.-Y. Feng, X.-G. Huang, and Q.-Y. Xiang, "A dual-band bandpass filter with a tunable passband," Progress In Electromagnetics Research C, Vol. 37, 107-118, 2013.

3. 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.
doi:10.2528/PIER11112304

4. Huang, X.-G., Q.-Y. Feng, Q.-Y. Xiang, and D.-H. Jia, "A high selectivity dual-band bandpass filter using dual-mode and triple-mode resonators," Progress In Electromagnetics Research C, Vol. 36, 81-90, 2013.

5. Xu, J. and W. Wu, "Compact microstrip dual-mode dual-band band-pass filters using stubs loaded coupled line," Progress In Electromagnetics Research C, Vol. 41, 137-150, 2013.

6. Wu, Y.-L., C. Liao, X.-Z. Xiong, and X.-M. Zhong, "Design filters using tunable E-shaped dual-mode resonators for lower-ultra-wideband and upper-ultra-wideband applications," Progress In Electromagnetics Research C, Vol. 37, 145-157, 2013.

7. Wang, Z.-D., F. Wei, L. Zhang, and X.-W. Shi, "Compact tunable dual-band bandpass filter based on substrate integrated waveguide and defected ground structure," Progress In Electromagnetics Research Letters, Vol. 41, 193-203, 2013.

8. Li, Y., H.-C. Yang, and S.-Q. Xiao, "Design of dual band filter based on a novel DGS structure," Progress In Electromagnetics Research Letters, Vol. 41, 167-174, 2013.

9. 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.

10. Kuo, J.-T., C.-Y. Fan, and S.-C. Tang, "Dual-wideband bandpass filters with extended stopband based on coupled-line and coupled three-line resonators," Progress In Electromagnetics Research, Vol. 124, 1-15, 2012.
doi:10.2528/PIER11120103

11. Zhou, C.-X., Y.-X. Guo, L. Wang, and W. Wu, "Design of compact dual-band filter in multilayer LTCC with cross coupling," Progress In Electromagnetics Research, Vol. 135, 515-525, 2013.

12. Deng, K., S. Yang, S.-J. Sun, B. Wu, and X.-W. Shi, "Dual-mode dual-band bandpass filter based on square loop resonator," Progress In Electromagnetics Research C, Vol. 37, 119-130, 2013.

13. Liu, Y., H.-X. Zheng, and L.-Y. Feng, "A compact dual-mode resonator with square loops and its bandpass filter applications," Progress In Electromagnetics Research Letters, Vol. 41, 51-61, 2013.

14. Liu, J.-C., F.-S. Huang, C.-P. Kuei, and C.-Y. Liu, "Compact dual-mode double square-loop resonators for WLAN and WiMAX tri-band filter design," Progress In Electromagnetics Research C, Vol. 38, 101-113, 2013.

15. Luo, S., L. Zhu, and S. Sun, "A dual-band ring-resonator bandpass filter based on two pairs of degenerate modes," IEEE Trans. Microw. Theory Tech., Vol. 58, No. 12, 3427-3432, 2010.

16. Huang, T.-H., H.-J. Chen, C.-S. Chang, L.-S. Chen, 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, 2006.
doi:10.1109/LMWC.2006.875607

17. 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 filter," IEEE Trans. Microw. Theory Tech., Vol. 61, No. 9, 3209-3215, 2013.
doi:10.1109/TMTT.2013.2273895

18. Sun, S.-J., B. Wu, T. Su, K. Deng, and C.-H. Liang, "Wideband dual-mode microstrip filter using short-ended resonator with centrally loaded inductive stub," IEEE Trans. Microw. Theory Tech., Vol. 60, No. 12, 3667-3673, 2012.
doi:10.1109/TMTT.2012.2221737

Dr. Kun Deng

Dr. Shou Jia Sun

Dr. Shuai Yang

Prof. Bian Wu

Professor Chang-Hong Liang