To achieve broadband microwave absorption, a three-layer structure is designed and manufactured. It involves a resistive frequency selective surface (FSS) sandwiched between two layers of magnetic sheets. The measurement results reveal that this structure exhibits -13 dB reflectivity in the frequency range of 7.9-18 GHz while the thickness is only 1.7 mm. The reflectivity bandwidth at the level of -10 dB is 11.4 GHz which is much wider than that of magnetic sheets with non-resistive FSS or the magnetic sheets without FSS. The effect of resistive FSS on the performance of the multilayered absorber is discussed in detail. It is concluded that an embedded resistive double loops FSS can result in a secondary resonance peak which obviously broadens the reflectivity bandwidth of the magnetic sheets.
1. Knott, E. F., J. F. Shaeffer, and M. T. Tuley, Radar Cross Section, 2nd Edition, Section 8, 314, SciTech, Raleigh, NC, 2004.
2. Yao, J., S. Bie, C. Zhang, and X. Chen, "Optimized design of the wave-absorbing coating made of carbonyl iron powders," Electronic Components and Materials, Vol. 31, 597-600, Jan. 2012.
3. Xiong, , J.-S. Hong, C.-M. Luo, and L.-L. Zhong, "An ultrathin and broadband metamaterial absorber using multi-layer structures," Journal of Applied Physics, Vol. 114, 064109-1-064109-6, Aug. 2013.
4. Babayan, V. A., Y. N. Kazantsev, A. V. Lopatin, V. P. Mal’tsev, and N. E. Kazantseva, "Extension of the operating frequency range of a dielectric radio absorber with the help of frequency selective surfaces," Journal of Communications Technology and Electronics, Vol. 56, 1357-1362, May 2011. doi:10.1134/S1064226911110040
5. Rozanov, K. N., "Ultimate thickness to bandwidth ratio of radar absorbers," IEEE Transactions on Antennas and Propagation, Vol. 48, 1230-1234, Aug. 2000. doi:10.1109/8.884491
6. Feng, Y. B., T. Qiu, and C. Y. Shen, "Absorbing properties and structural design of microwave absorbers based on carbonyl iron and barium ferrite," Journal of Magnetism and Magnetic Materials, Vol. 318, 8-13, Nov. 2007. doi:10.1016/j.jmmm.2007.04.012
7. Zhang, W., S. Bie, H. Chen, Y. Lu, and J. Jiang, "Electromagnetic and microwave absorption properties of carbonyl iron/MnO2 composite," Journal of Magnetism and Magnetic Materials, Vol. 323, 1805-1810, Apr. 2014.
8. Zhang, B., Y. Feng, J. Xiong, Y. Yang, and H. Lu, "Microwave absorbing properties of deaggregated flake-shaped carbonyl-iron particle composites at 2–18 GHz," IEEE Transactions on Magnetics, Vol. 42, 1778-1781, Jul. 2006. doi:10.1109/TMAG.2006.874188
9. Da Silva Macedo, J. A., M. J. de Sousa, and V. Dmitriev, "Optimization of wide-band multilayer microwave absorbers for any angle of incidence and arbitrary polarization," 2005 SBMO/IEEE MTT-S International Conference on Microwave and Optoelectronics, 558-561, Jul. 2005.
10. Chen, H.-Y., H.-B. Zhang, and L.-J. Deng, "Design of an ultra-thin magnetic-type radar absorber embedded with FSS," IEEE Antennas and Wireless Propagation Letters, Vol. 9, 899-901, Sep. 2010. doi:10.1109/LAWP.2010.2076344
11. Sha, Y., K. A. Jose, C. P. Neo, and V. K. Varadan, "Experimental investigations of microwave absorber with FSS embedded in carbon fiber composite," Microwave and Optical Technology Letters, Vol. 32, 245-249, Feb. 2002. doi:10.1002/mop.10144
12. Singh, D., A. Kumar, S. Meena, and V. Agarwala, "Analysis of frequency selective surfaces for radar absorbing materials," Progress In Electromagnetics Research B, Vol. 38, 297-314, Feb. 2012. doi:10.2528/PIERB11121601
13. Zhang, C., "Investigation of microwave absorption and conduction noise suppression properties for flake-shaped alloy magnetic powders,", Doctor Thesis, Huazhong University of Science and Technology, May 2012.
14. Cheng, Y.-Z. and X. Wang, "A wideband metamaterial absorber based on a magnetic resonator loaded with lumped resistors," Chin. Phys. B, Vol. 21, 127801-1-127801-5, Aug. 2012.