volume | PIER Journals

Abstract

To increase the stopband width of the filter, a second-order wide-stopband substrate-integrated waveguide filter is suggested. This filter is designed by utilizing a DGS structure and the weakest electric field approach. To suppress the modes, the filter sets the inner and outer coupling windows at the modes' weakest electric fields (TE₁₂₀/TE₂₁₀, TE₂₂₀). Additionally, a new nested U-shaped DGS structure is implemented to suppress the TE₁₃₀ mode, hence expanding the stopband width of the filter. The filter has been processed and measured, and the findings indicate a 4.5 GHz center frequency, a -3 dB bandwidth of 240 MHz, a relative bandwidth of 5.3%, an insertion loss of -1.2 dB in the passband, and a -22 dB stopband, which can be extended up to 9.4 GHz (i.e., 2.1 times the center frequency). The simulated and measured results demonstrate good alignment. Compared to other SIW filters, the current filter achieves a wider stopband while using fewer orders and implementing a straightforward design method, providing potential value for applications.

1. Bozzi, M., A. Georgiadis, and K. Wu, "Review of substrate-integrated waveguide circuits and antennas," IET Microwaves, Antennas & Propagation, Vol. 5, No. 8, 909-920, Jun. 2011.
doi:10.1049/iet-map.2010.0463

2. Chen, Xiao-Ping and Ke Wu, "Substrate integrated waveguide filter: Basic design rules and fundamental structure features," IEEE Microwave Magazine, Vol. 15, No. 5, 108-116, Jul.-Aug. 2014.

3. Moscato, Stefano, Cristiano Tomassoni, Maurizio Bozzi, and Luca Perregrini, "Quarter-mode cavity filters in substrate integrated waveguide technology," IEEE Transactions on Microwave Theory and Techniques, Vol. 64, No. 8, 2538-2547, Aug. 2016.
doi:10.1109/TMTT.2016.2577690

4. Jones, Thomas R. and Mojgan Daneshmand, "Miniaturized folded ridged half-mode and quarter-mode substrate integrated waveguides for filter design," IEEE Transactions on Microwave Theory and Techniques, Vol. 67, No. 8, 3414-3426, Aug. 2019.
doi:10.1109/TMTT.2019.2918519

5. Liu, Qing, Dewei Zhang, Min Tang, Hailin Deng, and Dongfang Zhou, "A class of box-like bandpass filters with wide stopband based on new dual-mode rectangular SIW cavities," IEEE Transactions on Microwave Theory and Techniques, Vol. 69, No. 1, 101-110, Jan. 2021.
doi:10.1109/TMTT.2020.3037497

6. Yun, Tae-Soon, Hee Nam, Jin-Young Kim, et al. "Harmonics suppressed substrate-integrated waveguide filter with integration of low-pass filter," Microwave and Optical Technology Letters, Vol. 50, No. 2, 447-450, 2008.

7. Zhou, Kang, Chunxia Zhou, and Wen Wu, "Substrate integrated waveguide dual-band filter with wide-stopband performance," Electronics Letters, Vol. 53, No. 16, 1121-1123, Aug. 2017.
doi:10.1049/el.2017.1556

8. Chu, Peng, Kai-Lai Zheng, Feng Xu, and Ke Wu, "Substrate integrated waveguide resonator with harmonic suppression," Electronics Letters, Vol. 54, No. 24, 1388-1389, Nov. 2018.
doi:10.1049/el.2018.6154

9. Chu, Peng, Lei Guo, Long Zhang, Feng Xu, Wei Hong, and Ke Wu, "Wide stopband substrate integrated waveguide filter implemented by orthogonal ports' offset," IEEE Transactions on Microwave Theory and Techniques, Vol. 68, No. 3, 964-970, Mar. 2020.
doi:10.1109/TMTT.2019.2947894

10. Zhou, Kang, Chun-Xia Zhou, and Wen Wu, "Resonance characteristics of substrate-integrated rectangular cavity and their applications to dual-band and wide-stopband bandpass filters design," IEEE Transactions on Microwave Theory and Techniques, Vol. 65, No. 5, 1511-1524, May 2017.
doi:10.1109/TMTT.2016.2645156

11. Zhu, F., W. Hong, J. X. Chen, and K. Wu, "Wide stopband substrate integrated waveguide filter using corner cavities," Electronics Letters, Vol. 49, No. 1, 50-52, Jan. 2013.
doi:10.1049/el.2012.3891

12. Jia, Dinghong, Quanyuan Feng, Qianyin Xiang, and Ke Wu, "Multilayer substrate integrated waveguide (SIW) filters with higher-order mode suppression," IEEE Microwave and Wireless Components Letters, Vol. 26, No. 9, 678-680, Sep. 2016.
doi:10.1109/LMWC.2016.2597222

13. Yang, Hong, Dongya Shen, Liang Li, Qiang Kang, and Kaibo Kai, "Integrated substrate gap waveguide bandpass filter with wide stopband," 2023 16th UK-Europe-China Workshop on Millimetre Waves and Terahertz Technologies (UCMMT), 1-3, Guangzhou, China, 2023.

14. Su, Zhi Li, Bo Wei Xu, Shao Yong Zheng, Hai Wen Liu, and Yun Liang Long, "High-isolation and wide-stopband SIW diplexer using mixed electric and magnetic coupling," IEEE Transactions on Circuits and Systems II: Express Briefs, Vol. 67, No. 1, 32-36, Jan. 2020.
doi:10.1109/TCSII.2019.2903388

15. Kim, Phirun and Yongchae Jeong, "Compact and wide stopband substrate integrated waveguide bandpass filter using mixed quarter-and one-eighth modes cavities," IEEE Microwave and Wireless Components Letters, Vol. 30, No. 1, 16-19, Jan. 2020.
doi:10.1109/LMWC.2019.2954603

Dr. Yuxin Fang

Prof. Xiaohei Yan

Dr. Yixian Wang

Dr. Shengbing Zhang