volume | PIER Journals

Abstract

In order to achieve miniaturization and high performance in microwave filters, this paper proposes two double-layer bandpass filters with different structures, both equivalent to square-coupled topologies. These filters employ dual-cavity single-mode and single-cavity dual-mode substrate-integrated waveguide resonators. In this configuration, the upper layer comprises two single-mode resonators connected to the input and output feed lines, while the lower layer contains dual-mode resonators coupled to the upper layer's single-mode resonators through two slots on the middle metal layer. A comprehensive analysis is conducted on the impact of primary parameters on filter characteristics and transmission zero positions. The second filter is fabricated and tested, yielding results consistent with simulation outcomes. The center frequency of the filter is 4.77 GHz, with a 3 dB bandwidth of 0.16 GHz (relative bandwidth: 3.35%). Additionally, its rectangularity coefficient at 10 dB approximately equals one, an ideal value for practical applications.

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2. 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, 2019.

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10. Chu, Peng, Wei Hong, Mingguang Tuo, Kai-Lai Zheng, Wen-Wen Yang, Feng Xu, and Ke Wu, "In-line ports dual-mode substrate integrated waveguide filter with flexible responses," IEEE Microwave and Wireless Components Letters, Vol. 28, No. 10, 882-884, 2018.

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13. Chu, Peng, Wei Hong, Mingguang Tuo, Kai-Lai Zheng, Wen-Wen Yang, Feng Xu, and Ke Wu, "Dual-mode substrate integrated waveguide filter with flexible response," IEEE Transactions on Microwave Theory and Techniques, Vol. 65, No. 3, 824-830, 2017.

14. Liu, Qing, Dongfang Zhou, Dalong Lv, Dewei Zhang, Junjie Zhang, and Yi Zhang, "Multi-layered dual-mode substrate integrated waveguide bandpass filter with input and output ports located on same substrate layer," IET Microwaves, Antennas & Propagation, Vol. 13, No. 15, 2641-2648, 2019.

15. Lee, Tae-Hak, Wentao Lin, and Ke Wu, "Multilayer SIW dual-mode bandpass filter with higher-order mode attenuation," 2018 IEEE MTT-S International Wireless Symposium (IWS), 1-3, Chengdu, China, 2018.

16. Liu, Qing, Dong-Fang Zhou, Ke Gong, Jian-Hui Wang, De-We Zhang, and Ben-Hua Ma, "Dual- and triple-mode single-layer substrate-integrated waveguide filters based on higher-order modes for millimeter-wave applications," IEEE Transactions on Circuits and Systems II: Express Briefs, Vol. 71, No. 4, 1994-1998, Apr. 2024.

17. Zhu, Fang, Guo Qing Luo, Bin You, Xiao Hong Zhang, and Ke Wu, "Planar dual-mode bandpass filters using perturbed substrate-integrated waveguide rectangular cavities," IEEE Transactions on Microwave Theory and Techniques, Vol. 69, No. 6, 3048-3057, Jun. 2021.

Prof. Xiaohei Yan

Professor Wenjing Mu