The rapid development of telecommunication systems has promoted the research of electromagnetic metamaterial absorbers. Based on the equivalent circuit theory, this paper proposes and designs a broadband absorption absorber based on electromagnetic metamaterials, which adopts a sandwich structure with an overall absorber thickness of 3.234 mm. The results show that the absorber has an absorption rate of more than 90% in the X-, Ku-, and K-bands (8.06 GHz-18.46 GHz) for the incident angle varying in the range of 0-50°. The absorption rate is higher than 90% for TE and TM mode electromagnetic waves and electromagnetic waves with polarization angle in the range of 0-50°. The absorber still has good absorption characteristics. The study shows that the absorber has small size, thin thickness, and broad angle broadband absorption characteristics.
13. Yoo, Y. J., et al., "Flexible and elastic metamaterial absorber for low frequency, based on small-size unit cell," Applied Physics Letters, Vol. 105, No. 4, 041902, 2014. doi:10.1063/1.4885095
14. Ghosh, S., et al., "Triple-band polarization-independent metamaterial absorber using destructive interference," 2015 European Microwave Conference (EuMC), 335-338, IEEE, 2015. doi:10.1109/EuMC.2015.7345768
15. Bhattacharyya, S., S. Ghosh, and K. V. Srivastava, "An ultra-thin polarization independent metamaterial absorber for triple band applications," 2013 IEEE Applied Electromagnetics Conference (AEMC), 1-2, IEEE, 2013.
17. Hu, D., et al., "Optically transparent broadband microwave absorption metamaterial by standing-up closed-ring resonators," Advanced Optical Materials, Vol. 5, No. 13, 1700109, 2017. doi:10.1002/adom.201700109
18. Amiri, M., et al., "Miniature tri-wideband Sierpinski-Minkowski fractals metamaterial perfect absorber," IET Microwaves, Antennas & Propagation, Vol. 13, No. 7, 991-996, 2019. doi:10.1049/iet-map.2018.5837
19. Huang, D., et al., "A second-order cross fractal meta-material structure used in low-frequency microwave absorbing materials," Applied Physics A, Vol. 115, No. 2, 627-635, 2014. doi:10.1007/s00339-014-8374-7
20. Nie, Y., Y. Z. Cheng, and R. Z. Gong, "A low-frequency wideband metamaterial absorber based on a cave-disk resonator and resistive film," Chinese Physics B, Vol. 22, No. 4, 044102, 2013. doi:10.1088/1674-1056/22/4/044102
21. Singh, A. K., M. P. Abegaonkar, and S. K. Koul, "Dual-and triple-band polarization insensitive ultrathin conformal metamaterial absorbers with wide angular stability," IEEE Transactions on Electromagnetic Compatibility, Vol. 61, No. 3, 878-886, 2018. doi:10.1109/TEMC.2018.2839881
22. Wang, Y., et al., "Experimental analysis and comparison between cross-shaped metamaterial absorber and its complementary structure," Microwave and Optical Technology Letters, Vol. 61, No. 4, 930-936, 2019. doi:10.1002/mop.31666
23. Yuan, W. and Y. Cheng, "Low-frequency and broadband metamaterial absorber based on lumped elements: Design, characterization and experiment," Applied Physics A, Vol. 117, No. 4, 1915-1921, 2014. doi:10.1007/s00339-014-8637-3