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PIER PIER B PIER C PIER M PIER Letters
2024-05-04
Multi-Characteristic Integrated Ultra-Wideband Frequency Selective Rasorber
By
Dengpan Wang,

    Dr. Dengpan Wang

    Air and Missile Defense College

    Air Force Engineering University

    China

    Homepage

Xingshuo Cui,

    Dr. Xingshuo Cui

    Air and Missile Defense College

    Air Force Engineering University

    China

    Homepage

Dan Liu,

    Dr. Dan Liu

    The Electromagnetics Academy at Zhejiang University

    China

    Homepage

Xiaojun Zou,

    Mr. Xiaojun Zou

    College of Information and Communication

    National University of Defense Technology

    China

    Homepage

Guang-Ming Wang,

    Professor Guang-Ming Wang

    Air and Missile Defense College

    Air Force Engineering University

    China

    Homepage

Bin Zheng,

    Dr. Bin Zheng

    Zhejiang University

    China

    Homepage

Tong Cai

    Dr. Tong Cai

    Air and Missile Defense College

    Air Force Engineering University

    China

    Homepage

Progress In Electromagnetics Research, Vol. 179, 49-59, 2024
doi:10.2528/PIER23060602
Abstract
Frequency selective rasorbers (FSRs), especially those with ultra-wideband and hybrid characteristics, are of great significance in modern stealth technology and applications. However, currently available FSRs have issues with limited transmission bandwidth and single operating characteristics. Here, a novel strategy is proposed to design multi-characteristic integrated FSRs with ultra-wide and high-efficiency passband via spoof surface plasmon polariton (SSPP). The designed FSR exhibits the characteristics of absorption-transmission (AT), transmission-absorption (TA), and absorption-transmission-absorption (ATA), which consists of AT resistive sheets, TA SSPP slow-wave structures, and ultra-wideband bandpass frequency selective surface (FSS). The top lumped-resistor-loaded resistive sheet and the bottom multi-layer cascaded FSS form an AT FSR which is demonstrated by equivalent circuit model (ECM). Middle dispersion gradient SSPP structure that generates SSPP on the periodic array is an independent TA FSR while the working principle is based on k-dispersion control and energy distribution. Thus, the transition band between the transmissive and absorptive bands is narrowed while the crosstalk between absorber and transmission is avoided. For verification, a prototype is fabricated and experimentally demonstrated. Measured results manifest the validity and feasibility of the FSR with an ultra-wide -1 dB transmission band from 8.9 to 16.4 GHz (59.3%) and two 85% absorption bands covering 2.2-6.4 GHz (97.7%) and 17.6-26 GHz (38.5%). Our work provides a novel method for the design of ultra-wideband multi-characteristic FSR and stimulates its application in broadband electromagnetic stealth, shielding and compatible devices.
Citation
Dengpan Wang, Xingshuo Cui, Dan Liu, Xiaojun Zou, Guang-Ming Wang, Bin Zheng, and Tong Cai, "Multi-Characteristic Integrated Ultra-Wideband Frequency Selective Rasorber," Progress In Electromagnetics Research, Vol. 179, 49-59, 2024.
doi:10.2528/PIER23060602
References

1. Yuan, Jing, Xiangkun Kong, Kai Chen, Xueqi Shen, Qi Wang, and Chen Wu, "Intelligent radome design with multilayer composites to realize asymmetric transmission of electromagnetic waves and energy isolation," IEEE Antennas and Wireless Propagation Letters, Vol. 19, No. 9, 1511-1515, 2020.

2. Bakshi, Saikat Chandra, Debasis Mitra, and Fernando L. Teixeira, "FSS-based fully reconfigurable rasorber with enhanced absorption bandwidth and simplified bias network," IEEE Transactions on Antennas and Propagation, Vol. 68, No. 11, 7370-7381, 2020.

3. Pang, Yongqiang, Yongfeng Li, Bingyue Qu, Mingbao Yan, Jiafu Wang, Shaobo Qu, and Zhuo Xu, "Wideband RCS reduction metasurface with a transmission window," IEEE Transactions on Antennas and Propagation, Vol. 68, No. 10, 7079-7087, 2020.

4. Yu, Shixing, Na Kou, Zhao Ding, and Zhengping Zhang, "Harmonic-absorption frequency selective rasorber based on non-resonant FSS and resistive-sheet," IEEE Transactions on Microwave Theory and Techniques, Vol. 69, No. 8, 3737-3745, 2021.

5. Wang, Dengpan, Yaqiang Zhuang, Lian Shen, Xiangyang Meng, Guangming Wang, Shiwei Tang, and Tong Cai, "Stealth radome with an ultra-broad transparent window and a high selectivity transition band," Optics Express, Vol. 30, No. 10, 16009-16019, 2022.

6. Sima, Boyu, Ke Chen, Na Zhang, Junming Zhao, Tian Jiang, and Yijun Feng, "Wideband low reflection backward scattering with an inter-band transparent window by phase tailoring of a frequency-selective metasurface," Journal of Physics D: Applied Physics, Vol. 55, No. 1, 015106, 2021.

7. Wang, Yuxiang, Yueyi Yuan, Guohui Yang, Xumin Ding, Qun Wu, Yannan Jiang, Shah Nawaz Burokur, and Kuang Zhang, "Perfect control of diffraction patterns with phase-gradient metasurfaces," ACS Applied Materials & Interfaces, Vol. 14, No. 14, 16856-16865, 2022.

8. Chen, Jiayu, Weihan Li, Yunfeng Zhang, Wenyu Ma, Wenxuan Tang, and Tiejun Cui, "Absorption-transmission-type multifunctional coding metasurface," Journal of Physics D: Applied Physics, Vol. 55, No. 40, 405003, 2022.

9. Wang, Zanyang, Guangming Wang, Xingshuo Cui, and Hao Bai, "Hybrid metasurface-based broadband high gain stealth antenna," Optics Express, Vol. 30, No. 18, 32833-32846, 2022.

10. Wu, Lijie, Shuomin Zhong, Jifu Huang, and Taijun Liu, "Broadband frequency-selective rasorber with varactor-tunable interabsorption band transmission window," IEEE Transactions on Antennas and Propagation, Vol. 67, No. 9, 6039-6050, 2019.

11. Guo, Min, Tiantian Guo, Qiang Cheng, Yuejun Zheng, and Yunqi Fu, "Frequency selective rasorber with anisotropic transmission band," IEEE Antennas and Wireless Propagation Letters, Vol. 20, No. 2, 155-159, 2021.

12. Wang, Lingling, Shaobin Liu, Xiangkun Kong, Qiming Yu, Xuewei Zhang, and Haifeng Zhang, "A multifunctional hybrid frequency-selective rasorber with a high-efficiency cross-polarized passband/co-polarized specular reflection band," IEEE Transactions on Antennas and Propagation, Vol. 70, No. 9, 8173-8183, 2022.

13. Chen, Hao, Xiao-Li Peng, Xin-Zhi Bo, Ming-Yang Geng, Xiao-Lu Yang, Jun-Lin Zhan, Zhen-Guo Liu, Yun-Qian Dai, and Wei-Bing Lu, "All-fabric flexible frequency-selective-rasorber based on cutting-transfer patterning method," Advanced Materials Interfaces, Vol. 9, No. 23, 2200651, 2022.

14. Xue, Kun and Huiqing Zhai, "A compact ultrawideband frequency selective rasorber with hybrid 2-D and 3-D structure," IEEE Antennas and Wireless Propagation Letters, Vol. 21, No. 9, 1872-1876, 2022.

15. Ma, Zheyipei, Chao Jiang, Jiale Li, and Xiaozhong Huang, "A dual-transmission-bands rasorber with improved absorption and oblique incidence performance," Scientific Reports, Vol. 12, No. 1, 20599, 2022.

16. Yu, Dingwang, Yanfei Dong, Zhuohang Zhang, Mingtuan Lin, and Lujing Han, "High-selectivity frequency-selective rasorber with tunable absorptivity," IEEE Transactions on Antennas and Propagation, Vol. 71, No. 4, 3620-3630, 2023.

17. Wang, Zhefei, Jiahui Fu, Qingsheng Zeng, Mingxin Song, and Tayeb Ahmed Denidni, "Wideband transmissive frequency-selective absorber," IEEE Antennas and Wireless Propagation Letters, Vol. 18, No. 7, 1443-1447, 2019.

18. Dai, Yilin, Yang Fu, Shiju Chen, Jiong Wu, Shanshan Liu, Zhaoyang Shen, and Helin Yang, "Miniaturized frequency selective rasorber with absorption in S-C band and transmission in X band," Physica Scripta, Vol. 98, No. 2, 025506, 2023.

19. Li, Minhua, Congying Huang, Chengye Huang, Youting Song, Hanru Shao, and Jianfeng Dong, "Graphene integrated rasorber at terahertz frequencies with functionalities of both absorption and transmission," Results in Physics, Vol. 41, 105959, 2022.

20. Shen, Zhaoshuzhou, Na Kou, Shixing Yu, Zhao Ding, and Zhengping Zhang, "Miniaturized frequency selective rasorber based on meander-lines loaded lumped resistors and a coupled resonator spatial filter," Progress In Electromagnetics Research M, Vol. 90, 147-155, 2020.

21. Yu, Shixing, Na Kou, Zhao Ding, and Zhengping Zhang, "Harmonic-suppressed frequency selective rasorber using resistive-film sheet and square-loops resonator," IEEE Antennas and Wireless Propagation Letters, Vol. 19, No. 2, 292-296, 2020.

22. Lin, Chun-Wen, Chi-Kai Shen, and Tzong-Lin Wu, "Ultracompact via-based absorptive frequency-selective surface for 5-GHz Wi-Fi with passbands and high-performance stability," IEEE Transactions on Components, Packaging and Manufacturing Technology, Vol. 8, No. 1, 41-49, 2018.

23. Shah, Gulab, Qunsheng Cao, Zaheer Ahmed Dayo, and Muhammad Azeem, "Double layer multifunction frequency selective surface equipped with a tricharacteristic response," IEEE Transactions on Electromagnetic Compatibility, Vol. 64, No. 2, 295-302, 2022.

24. Jia, Yuxin, Yani Wang, Jiao Yin, Chaozong Guo, Huiqing Zhai, and Changyuan Liu, "Design of a hybrid frequency selective rasorber with wideband reflection suppression," IEEE Antennas and Wireless Propagation Letters, Vol. 22, No. 2, 293-297, 2023.

25. Ye, Hang, Jianfeng Wei, Li Lin, Fucheng Liu, Ling Miao, Shaowei Bie, and Jianjun Jiang, "A frequency-selective surface rasorber based on four functional layers," IEEE Transactions on Antennas and Propagation, Vol. 69, No. 5, 2768-2778, 2021.

26. Mao, Zhiwen, Kun Xu, Xiaomei Qian, and Xianying Chu, "A global-local design method for wideband absorption/transmission sandwich rasorber with frequency-selective surfaces," Composite Structures, Vol. 322, 117401, 2023.

27. Rao, Tingli, Shixing Yu, Rongyang Shi, and Na Kou, "A dielectric matching layer loaded frequency selective rasorber with enhanced angular stabilities," IEEE Antennas and Wireless Propagation Letters, Vol. 22, No. 7, 1552-1556, 2023.

28. Huang, Hao, Changzhou Hua, and Zhongxiang Shen, "Absorptive frequency-selective transmission structures based on hybrid FSS and absorber," IEEE Transactions on Antennas and Propagation, Vol. 70, No. 7, 5606-5613, 2022.

29. Ye, Hang, Wentao Dai, Xu Chen, Hao Zhang, Shaowei Bie, and Jianjun Jiang, "High-selectivity frequency-selective rasorber based on low-profile bandpass filter," IEEE Antennas and Wireless Propagation Letters, Vol. 20, No. 2, 150-154, 2021.

30. Guo, Min, Di Sang, Fang Yuan, Tiantian Guo, Yuejun Zheng, Qiang Chen, and Yunqi Fu, "Broadband absorptive frequency-selective rasorber based on multilayer resistive sheets using multilayer resonator," IEEE Transactions on Antennas and Propagation, Vol. 70, No. 3, 2009-2022, 2022.

31. Yang, Yaojia, Bian Wu, Biao Chen, and Yutong Zhao, "Flexible frequency-selective rasorber based on metal-graphene hybrid metamaterial," Optics Express, Vol. 30, No. 5, 6566-6576, 2022.

32. Chen, Qiang, Di Sang, Min Guo, and Yunqi Fu, "Miniaturized frequency-selective rasorber with a wide transmission band using circular spiral resonator," IEEE Transactions on Antennas and Propagation, Vol. 67, No. 2, 1045-1052, 2019.

33. Wang, Lingling, Shaobin Liu, Xiangkun Kong, Haifeng Zhang, Qiming Yu, and Yongdiao Wen, "Frequency-selective rasorber with a wide high-transmission passband based on multiple coplanar parallel resonances," IEEE Antennas and Wireless Propagation Letters, Vol. 19, No. 2, 337-340, 2020.

34. Xing, Qijun, Weiwei Wu, Yuchen Yan, Ximeng Zhang, and Naichang Yuan, "A wideband frequency-selective rasorber with rectangular spiral resonators," IEEE Antennas and Wireless Propagation Letters, Vol. 21, No. 8, 1688-1692, 2022.

35. Yang, Zeqian, Wen Jiang, Qiulin Huang, and Tao Hong, "A 2.5-D miniaturized frequency-selective rasorber with a wide high-transmission passband," IEEE Antennas and Wireless Propagation Letters, Vol. 20, No. 7, 1140-1144, 2021.

36. Zhu, Shengchi, Zhenxin Cao, Huaimin Zhou, Ruolin Geng, Guohu Deng, and Xin Quan, "Ultra-wide transmission band frequency-selective rasorber using 2.5-D miniaturized structures," Optics Express, Vol. 30, No. 19, 33980-33993, 2022.

37. Shen, Zhongxiang, Jiang Wang, and Bo Li, "3-D frequency selective rasorber: Concept, analysis, and design," IEEE Transactions on Microwave Theory and Techniques, Vol. 64, No. 10, 3087-3096, 2016.

38. Yu, Yufeng, Guo Qing Luo, Ahmed Abdelmottaleb Omar, Xuan Liu, Weiliang Yu, Zhang Cheng Hao, and Zhongxiang Shen, "3D absorptive frequency-selective reflection and transmission structures with dual absorption bands," IEEE Access, Vol. 6, 72880-72888, 2018.

39. Zhong, Shuomin, Jiaqi Feng, Zi-Wei Zheng, and Yungui Ma, "Ultrathin and simple 3-D rasorber based on ferrites with embedded epsilon-near-zero waveguides," IEEE Antennas and Wireless Propagation Letters, Vol. 21, No. 9, 1896-1900, 2022.

40. Kianinejad, Amin, Zhi Ning Chen, and Cheng-Wei Qiu, "Design and modeling of spoof surface plasmon modes-based microwave slow-wave transmission line," IEEE Transactions on Microwave Theory and Techniques, Vol. 63, No. 6, 1817-1825, 2015.

41. Wang, Chao, Yongfeng Li, Maochang Feng, Jiafu Wang, Hua Ma, Jieqiu Zhang, and Shaobo Qu, "Frequency-selective structure with transmission and scattering deflection based on spoof surface plasmon polariton modes," IEEE Transactions on Antennas and Propagation, Vol. 67, No. 10, 6508-6514, 2019.

42. Zhang, Dawei, Yaxiu Sun, Kuang Zhang, Qun Wu, and Tao Jiang, "Short-circuited stub-loaded spoof surface plasmon polariton transmission lines with flexibly controllable lower out-of-band rejections," Optics Letters, Vol. 46, No. 17, 4354-4357, 2021.

43. Zhu, Zhibiao, Yongfeng Li, Jieqiu Zhang, Jiafu Wang, Weipeng Wan, Lin Zheng, Mingde Feng, Hongya Chen, and Shaobo Qu, "Absorptive frequency selective surface with two alternately switchable transmission/reflection bands," Optics Express, Vol. 29, No. 3, 4219-4229, 2021.

44. Wang, Dengpan, Kaiyue Liu, Xiaofeng Li, Guangming Wang, Shiwei Tang, and Tong Cai, "Bifunctional spoof surface plasmon polariton meta-coupler using anisotropic transmissive metasurface," Nanophotonics, Vol. 11, No. 6, 1177-1185, 2022.

45. Liu, Yiqun, Kai-Da Xu, Jianxing Li, Ying-Jiang Guo, Anxue Zhang, and Qiang Chen, "Millimeter-wave E-plane waveguide bandpass filters based on spoof surface plasmon polaritons," IEEE Transactions on Microwave Theory and Techniques, Vol. 70, No. 10, 4399-4409, 2022.

46. Yu, Jun, Wen Jiang, and Shuxi Gong, "Wideband angular stable absorber based on spoof surface plasmon polariton for RCS reduction," IEEE Antennas and Wireless Propagation Letters, Vol. 19, No. 7, 1058-1062, 2020.

47. Deng, Taowu, Jiangang Liang, Tong Cai, Canyu Wang, Xin Wang, Jing Lou, Zhiqiang Du, and Dengpan Wang, "Ultra-thin and broadband surface wave meta-absorber," Optics Express, Vol. 29, No. 12, 19193-19201, 2021.

48. Cheng, Linhao, Yuan Si, Zhengjiang Ji, Jianhui Xu, Jiachen Dong, Zhiheng He, Ruilin Huang, Lin Zheng, Leilei Yan, and Xitao Zheng, "A novel linear gradient carbon fiber array integrated square honeycomb structure with electromagnetic wave absorption and enhanced mechanical performances," Composite Structures, Vol. 305, 116510, 2023.

49. Zhang, Qi, Zhongxiang Shen, Jianpeng Wang, and Kian Seng Lee, "Design of a switchable microwave absorber," IEEE Antennas and Wireless Propagation Letters, Vol. 11, 1158-1161, 2012.

50. Langley, Richard J. and Edward A. Parker, "Equivalent circuit model for arrays of square loops," Electronics Letters, Vol. 18, No. 7, 294-296, 1982.

51. Ferreira, David, Rafael F. S. Caldeirinha, Iñigo Cuiñas, and Telmo R. Fernandes, "Square loop and slot frequency selective surfaces study for equivalent circuit model optimization," IEEE Transactions on Antennas and Propagation, Vol. 63, No. 9, 3947-3955, 2015.

52. Ma, Xin, Guobin Wan, Wenwu Zhang, Yifei Mu, and Xuying Tang, "Synthesis of second-order wide-passband frequency selective surface using double-periodic structures," IET Microwaves, Antennas & Propagation, Vol. 13, No. 3, 373-379, 2019.

53. Pozar, David M., Microwave Engineering, 4th Ed., John Wiley & Sons, New York, NY, USA, 2012.

54. Jia, Yuxin, Yani Wang, Jiao Yin, Chaozong Guo, Huiqing Zhai, and Changyuan Liu, "Design of a hybrid frequency selective rasorber with wideband reflection suppression," IEEE Antennas and Wireless Propagation Letters, Vol. 22, No. 2, 293-297, 2023.

55. Yu, Weiliang, Mengmeng Cheng, Yufeng Yu, Wenlei Wang, Leilei Liu, and Guo Qing Luo, "Bandpass absorptive frequency-selective structures with wide absorption bands based on hybrid 2-D and 3-D structures," IEEE Transactions on Antennas and Propagation, Vol. 71, No. 4, 3183-3192, 2023.

56. Malekara, Asal, Amin Khalilzadegan, Changiz Ghobadi, and Javad Nourinia, "Wide-angle, dual-polarized frequency selective rasorber based on the electric field coupled resonator using characteristic mode analysis," Journal of Applied Physics, Vol. 133, No. 16, 164504, 2023.

57. Cai, T., S. W. Tang, B. Zheng, G. M. Wang, W. Y. Ji, C. Qian, Z. J. Wang, E. P. Li, and H. S. Chen, "Ultrawideband chromatic aberration-free meta-mirrors," Advanced Photonics, Vol. 3, No. 1, 016001, 2021.

58. Cai, T., B. Zheng, J. Lou, L. Shen, Y. H. Yang, S. W. Tang, E. P. Li, C. Qian, and H. S. Chen, "Experimental realization of a superdispersion-enabled ultrabroadband terahertz cloak," Advanced Materials, Vol. 34, No. 38, 2205053, 2022.

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