volume | PIER Journals

Abstract

This letter proposes a compact single-layer balanced bandpass filter (BPF), which is realized by a new arrangement of eighth-mode substrate integrated waveguide (EMSIW) cavities. Under differential-mode (DM) operation, the half bisection topology of the proposed EMSIW filter can be equivalent to a quadruplet scheme based on four coupled EMSIW cavities. The negative cross coupling can be easily realized by the nature of the fringe electric fields of opened ends of EMSIW cavities. For the demonstration, a balanced EMSIW filter with the operating frequency at 2.4 GHz is designed, fabricated, and measured.

1. Wei, F., P. Qin, Y. J. Guo, C. Ding, and X. W. Shi, "Compact balanced dual- and tri-band bpfs based on coupled complementary split-ring resonators (C-CSRR)," IEEE Microwave and Wireless Components Letters, Vol. 26, No. 2, 107-109, 2016.
doi:10.1109/LMWC.2016.2517125

2. Wei, F., Y. J. Guo, P. Qin, and X. W. Shi, "Compact balanced dual- and tri-band bandpass filters based on stub loaded resonators," IEEE Microwave and Wireless Components Letters, Vol. 25, No. 2, 76-78, 2015.
doi:10.1109/LMWC.2014.2370233

3. Yang, Z.-J., Y.-Y. Shan, X.-T Zou, F. Wei, and B. Li, "A balanced bandpass filter with ultra-wide stopband and common-mode suppression," Progress In Electromagnetics Research Letters, Vol. 77, 123-128, 2018.
doi:10.2528/PIERL18062508

4. Deng, K. and Z. Chen, "Wideband balanced filters with wideband common mode suppression using coupled lines," Progress In Electromagnetics Research Letters, Vol. 65, 49-55, 2017.
doi:10.2528/PIERL16111201

5. Xu, X., J. Wang, and L. Zhu, "A new approach to design differential-mode bandpass filters on SIW structure," IEEE Microwave and Wireless Components Letters, Vol. 23, No. 12, 635-637, 2013.
doi:10.1109/LMWC.2013.2283859

6. Chu, P., W. Hong, K. Wang, et al. "Balanced substrate integrated waveguide filter," IEEE Transactions on Microwave Theory and Techniques, Vol. 62, No. 4, 824-831, 2014.
doi:10.1109/TMTT.2014.2307055

7. Chu, H., P. Li, and J. Chen, "Balanced substrate integrated waveguide bandpass filter with high selectivity and common-mode suppression," IET Microw., Antennas Propag., Vol. 9, No. 2, 133-141, 2015.
doi:10.1049/iet-map.2013.0708

8. Chu, P. and K. Wu, "Balanced dual-mode SIW filter," Electron. Lett., Vol. 55, No. 4, 208-210, 2019.
doi:10.1049/el.2018.7289

9. Li, P., H. Chu, D. Zhao, and R. S. Chen, "Compact dual-band balanced SIW bandpass filter with improved common-mode suppression," IEEE Microwave and Wireless Components Letters, Vol. 27, No. 4, 347-349, 2017.
doi:10.1109/LMWC.2017.2678428

10. Ho, M. and C. Li, "Novel balanced bandpass filters using substrate integrated half-mode waveguide," IEEE Microwave and Wireless Components Letters, Vol. 23, No. 2, 78-80, 2013.
doi:10.1109/LMWC.2013.2238911

11. Li, P., H. Chu, and R. Chen, "Design of compact bandpass filters using quarter-mode and eighthmode SIW cavities," IEEE Trans. Compon., Packag., Manuf. Technol., Vol. 7, No. 6, 956-963, 2017.
doi:10.1109/TCPMT.2017.2677958

12. Lu, J., C. Liao, and C. Chang, "Microstrip parallel-coupled filters with cascade trisection and quadruplet responses," IEEE Transactions on Microwave Theory and Techniques, Vol. 56, No. 9, 2101-2110, 2008.
doi:10.1109/TMTT.2008.2002226

Dr. Xiao-Bang Ji

Dr. Qing Liu

Dr. Mi Yang