PIER Letters
Progress In Electromagnetics Research Letters
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By Q. F. Su

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This paper presents a compact tri-band bandpass filter (BPF) with high selectivity. The proposed filter utilizes novel stub-loaded quarter-wavelength resonators and conventional uniform quarter-wavelength resonators. The latter is embedded in the former, and they are separated by a feed line. Due to these quarter-wavelength resonators, the total size is greatly reduced. Moreover, the passband frequencies can be controlled individually. To enhance its selectivity, source-load coupling is employed. For demonstration, an experimental filter is implemented. High skirt selectivity and suppression levels are observed in the measured results. The circuit area of the filter is 0.17λg×0.19λg, featuring compact size.

Q. F. Su, "Design of Novel Compact Tri-Band Bandpass Filter with Controllable Frequencies and High Selectivity," Progress In Electromagnetics Research Letters, Vol. 48, 109-115, 2014.

1. Chu, Q.-X. and X.-M. Lin, "Advanced triple-band bandpass filter using tri-section SIR," Electron. Lett., Vol. 44, No. 4, 295-296, 2008.

2. Hus, C. I. G., C. H. Lee, and Y. H. Hsieh, "Tri-band bandpass filter with sharp passband skirts designed using tri-section SIRs," IEEE Microw. Wireless Compon. Lett., Vol. 18, No. 1, 19-21, 2008.

3. Liu, B. and Y. Zhao, "Compact tri-band bandpass filter for WLAN and WiMAX using tri-section stepped-impedance resonators," Progress In Electromagnetics Research Letters, Vol. 45, 39-44, 2014.

4. Li, J., S. S. Huang, and J. Z. Zhao, "Design of a compact and high selectivity tri-band bandpass filter using asymmetric stepped-impedance resonators (SIRs)," Progress In Electromagnetics Research Letters, Vol. 44, 81-86, 2014.

5. Chen, F.-C., J.-M. Qiu, and Q.-X. Chu, "Design of compact tri-band bandpass filter using centrally loaded resonator," Microwave Opt. Tech. Lett., Vol. 55, No. 11, 2695-2699, 2013.

6. Fan, W. X., Z. P. Li, and S. X. Gong, "Tri-band filter using combined E-type resonators," Electron. Lett., Vol. 49, No. 1, 193-194, 2013.

7. Gao, L., X. Y. Zhang, B.-J. Hu, and Q. Xue, "Novel stub-loaded multi-mode resonators and their applications to various bandpass filters," IEEE Trans. Microw. Theory Tech., Vol. 62, No. 5, 1162-1172, 2014.

8. Li, Z., T. Su, and C. Zhao, "A novel compact triple-passband design based on stepped impedance stub-loaded resonators," Microw. Opt. Tech. Lett., Vol. 54, No. 9, 2106-2108, 2012.

9. Chen, W.-Y., M.-H. Weng, and S.-H. Chang, "A new tri-band bandpass filter based on stub-loaded step-impedance resonator," IEEE Microw. Wireless Compon. Lett., Vol. 22, No. 4, 179-181, 2012.

10. Ghatak, R., M. Pal, P. Sarkar, A. K. Aditya, and D. R. Poddar, "Tri-band bandpass filters using modified tri-section stepped impedance resonator with improved selectivity and wide upper stopband," IET Microw. Antennas Propag., Vol. 7, No. 15, 1187-1193, 2013.

11. Sun, S.-J., T. Su, K. Deng, B. Wu, and C.-H. Liang, "Shorted-ended stepped-impedance dualresonance resonator and its application to bandpass filters," IEEE Trans. Microw. Theory Tech., Vol. 61, No. 9, 3209-3215, 2013.

12. Chen, F. C., Q. X. Chu, and Z.-H. T, "Tri-band bandpass filter using stub loaded resonators," Electron. Lett., Vol. 44, No. 12, 747-749, 2008.

13. Chen, F. C. and Q. X. Chu, "Design of compact tri-band bandpass filters using assembled resonators," IEEE Trans. Microw. Theory Tech., Vol. 57, No. 1, 165-171, 2009.

14. Deng, H.-W., Y.-J. Zhao, X.-J. Zhou, Y. Fu, and Y.-Y. Liu, "Design of compact and high selectivity tri-band wideband microstrip BPF," Microwave Opt. Technol. Lett., Vol. 55, No. 2, 258-261, 2013.

15. Peng, Y., L. Zhang, Y. Leng, and J. Guan, "A compact tri-band passband filter based on three embedded bending stub resonators," Progress In Electromagnetics Research Letters, Vol. 37, 189-197, 2013.

16. Xu, K., Y. Zhang, D. Li, Y. Fan, J. L.-W. Li, W. T. Joine, 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.

17. 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, 2013.

18. Hong, J. S. and M. J. Lancaster, Microwave Filter for RF/Microwave Application, John Wiley & Sons, New York, 2001.

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