volume | PIER Journals

Abstract

In this paper, a compact tri-band microstrip bandpass filter (BPF) using tri-section stepped-impedance resonators (TSSIRs) with open stub line and zero-degree feed line is presented. Three tunable passbands are achieved by changing the ratio of impedance. By adding the open stub line, the frequency responses of tri-band at 2.4 GHz/3.5 GHz/5.2 GHz can be obtained precisely. With a proper length of the cone-shaped zero-degree feed structure, we can obtain transmission zeros in stopbands and better return loss in passbands. The proposed tri-band BPF has high selectivity and is simple in fabrication.

1. Li, C.-H., C.-L. Yeh, M. H. Huang, and S.-M.Wu, "A harmonic suppression bandpass filter designed by E-type SIR with shunt open stub," Proc. Asia-Paci¯c Microwave Conf., 1031-1034, Dec. 2011.

2. Zhang, S. and L. Zhu, "Compact tri-band bandpass filter based on λ/4 resonators with U-folded coupled-line," IEEE Microw. Wireless Compon. Lett., Vol. 23, No. 5, 258-260, May 2013.
doi:10.1109/LMWC.2013.2255868

3. Liu, W. P. and Y. W. Tun, "Tri-band filter with partly combined stepped-impedance resonators," Proc. Asia-Pacific Microwave Conf., 975-978, Dec. 2011.

4. Lin, X. M. and Q. X. Chu, "A novel tri-band filter with transmission zeros using tri-section SIR," International Conf. Microwave and Millimeter Wave Technology, 2008, ICMMT 2008, Vol. 3, 1261-1263, Apr. 2008.

5. Packiaraj, D., M. Ramesh, and A. T. Kalghatgi, "Design of a tri-section folded SIR filter," IEEE Microw. Wireless Compon. Lett., Vol. 16, No. 5, 317-319, May 2006.
doi:10.1109/LMWC.2006.873459

6. Malimoto, M. and S. Yamashita, "Bandpass filter using parallel coupled stripline stepped impedance resonators," IEEE Trans. Microw. Theory Tech., Vol. 28, No. 12, 1413-1417, Dec. 1980.
doi:10.1109/TMTT.1980.1130258

7. Chen, F. C. and Q. X. Chu, "Design of compact tri-band bandpass filters using assembled resonators," IEEE Trans. Microw. Theory Tech., Vol. 57, 165-171, 2009.
doi:10.1109/TMTT.2008.2008963

8. Chen, W.-Y., M.-H.Weng, S.-J. Chang, H. Kuan, and Y.-H. Su, "A new tri-band bandpass filter for GSM, WiMAX and ultra-wideband responses by using asymmetric stepped impedance resonators," Progress In Electromagnetics Research, Vol. 124, 365-381, 2012.
doi:10.2528/PIER11122010

9. Zhang, X.-Y., L. Gao, Z.-Y. Cai, and X.-L. Zha, "Novel tri-band bandpass filter using stub-loaded short-ended resonators," Progress In Electromagnetics Research Letters, Vol. 40, 81-92, 2013.
doi:10.2528/PIERL13040205

10. Zhang, J., J.-Z. Gu, B. Cui, and X. W. Sun, "Compact and harmonic suppression open-loop resonator bandpass filter with tri-section SIR," Progress In Electromagnetics Research, Vol. 69, 93-100, 2007.
doi:10.2528/PIER06120702

11. Xue, W., C.-H. Liang, X.-W. Dai, and J.-W. Fan, "Design of miniature dual-band filter with 0^o feed structures," Progress In Electromagnetics Research, Vol. 77, 493-499, 2007.
doi:10.2528/PIER07090502

12. Zhang, X.-Y., Q. Xue, and B.-J. Hu, "Planar tri-band bandpass filter with compact size," IEEE Microw. Wireless Compon. Lett., Vol. 20, No. 5, 262-264, May 2010.
doi:10.1109/LMWC.2010.2045583

13. Chu, Q.-X., X.-H. Wu, and F.-C. Chen, "Novel compact tri-band bandpass filter with controllable bandwidths," IEEE Microw. Wireless Compon. Lett., Vol. 21, No. 12, 655-657, Dec. 2011.
doi:10.1109/LMWC.2011.2172593

14. Chen, J.-Z., N. Wang, Y. He, and C.-H. Liang, "Fourth-order tri-band bandpass filter using square ring loaded resonators," Electron. Lett., Vol. 47, No. 15, 858-859, Jul. 2011.
doi:10.1049/el.2010.3724

15. 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.

16. Xu, K., Y. Zhang, D. Li, Y. Fan, J.-L.-W. Li, W.-T. Joines, and Q.-H. Liu, "Novel design of a compact triple-band bandpass filter using short stub-loaded SIRs and embedded SIRs structure," Progress In Electromagnetics Research, Vol. 142, 309-320, 2013.
doi:10.2528/PIER13080507

17. Doan, M.-T., Q.-T. Do, and V.-H. Tran, "Compact tri-band bandpass filter using embedded resonators with multiple transmission zeros," Advanced Technologies for Communications (ATC) 2012 International Conf., 345-348, Oct. 2012.

Dr. Bo Liu

Dr. Yimin Zhao