In this paper, a 3-dimensional metamaterial absorber operating at 11.8 GHz was presented. The metamaterial absorber is composed of coplanar magnetic and electric resonators, with the latter in the center part of the former. By carefully adjusting structural dimensions of magnetic and electric resonators, absorbance per unit cell can reach up to 96% at 11.8 GHz with a 6% FWHM (Full Width at Half Maximum). The full-wave simulations confirmed nearly equal permeability and permittivity and large imaginary part of the refractive index at 11.8 GHz and thus proved the effectiveness of the proposed 3-dimensional metamaterial absorber for microwave applications.
2. Pendry, J. B., A. J. Holden, D. J. Robbins, and W. J. Stewart, "Magnetism from conductors and enhanced nonlinear phenomena," IEEE Trans. Microwave Theory Tech., Vol. 47, 2075-2084, 1999.
3. Smith, D. R., W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz, "Composite medium with simultaneously negative permeability and permittivity," Phys. Rev. Lett., Vol. 84, 4184-4187, 2000.
4. Lagarkov, A. N., V. N. Kisel, and V. N. Semenenko, "Wide-angle absorption by the use of a metamaterial plate," Progress In Electromagnetics Research Letters, Vol. 1, 35-44, 2008.
5. Ourir, A., A. D. Lustrac, and J.-M. Lourtioz, "All-metamaterial-based subwavelength cavities λ/60 for ultrathin directive antennas," Appl. Phys. Lett., Vol. 88, 084103, 2006.
6. Alú, A., F. Bilotti, N. Engheta, and L. Vegni, "Sub-wavelength, compact, resonant patch antennas loaded with metamaterials," IEEE Trans. Antennas Propagat., Vol. 55, No. 1, 13-25, 2007.
7. Bilotti, F., A. Toscano, L. Vegni, K. B. Alici, K. Aydin, and E. Ozbay, "Equivalent circuit models for the design of metamaterials based on artificial magnetic inclusions," IEEE Trans. Microwave Theory Tech., Vol. 55, No. 12, 2865-2873, 2007.
8. A., F. Bilotti, N. Engheta, L. Vegni and A conformal omni-directional sub-wavelength metamaterial leaky-wave antenna, "Alú," IEEE Trans. Antennas Propagat., Vol. 55, No. 6, 1698-1708, 2007.
9. Xi, S., H. Chen, B.-I. Wu, and J. A. Kong, "Experimental confirmation of guidance properties using planar anisotropic left-handed metamaterial slabs based on S-ring resonators," Progress In Electromagnetics Research, Vol. 84, 279-287, 2008.
10. Ran, L., J. Huangfu, H. Chen, X. Zhang, K. Cheng, T. M. Grzegorczyk, T. M. Grzegorczyk, and , "Experimental study on several left-handed metamaterials," Progress in Electromagnetics Research, Vol. 51, 249-279, 2005.
11. Wongkasem, N., A. Akyurtlu, and K. A. Marx, "Group theory based design of isotropic negative refractive index metamaterials," Progress In Electromagnetics Research, Vol. 63, 295-310, 2006.
12. Wang, J. F., S. B. Qu, Z. Xu, J. Q. Zhang, Y. M. Yang, H. Ma, and C. Gu, "A candidate three-dimensional GHz lefthanded metamaterial composed of coplanar magnetic and electric resonators," Photonics Nanostruct.: Fundam. Appl., Vol. 6, 183-187, 2008.
13. Kisel, V. N. and A. N. Lagarkov, "Near-perfect absorption by a flat metamaterial plate," Phys. Rev. E, Vol. 76, 065601, 2007.
14. Kern, D. J. and D. H. Werner, "A generic algorithm approach to the design of ultra-thin electromagnetic band-gap absorber," Microwave Opt. Tech. Lett., Vol. 38, No. 1, 61-64, 2003.
15. Chakravarty, S., R. Mittra, and N. R. Williams, "On the pplication of the micro-Genetic Algorithm (MGA) to the design of broadband microwave absorbers comprising frequency selective surface (FSS) embedded in multilayered dielectric media," IEEE Trans. Microwave Theory Tech., Vol. 49, No. 6, 1050-1059, 2001.
16. Bilotti, F., L. Nucci, and L. Vegni, "An SRR based microwave absorber," Opt. Tech. Lett., Vol. 48, No. 11, 2171-2175, 2006.
17. Landy, N. I., S. Sajuyigbe, J. J. Mock, D. R. Smith, S. Sajuyigbe, J. J. Mock, D. R. Smith, and , "Perfect metamaterial absorber," Phys. Rev. Lett., Vol. 100, 207402, 2008.
18. Tao, H., N. I. Landy, C. M. Bingham, X. Zhang, R. D. Averitt, and W. J. Padilla, "A metamaterial absorber for the terahertz regime: Design, fabrication and characterization," Opt. Express, Vol. 16, No. 10, 7181-7188, 2008.
19. Ahmadi, A. and H. Mosallaei, "Physical configuration and performance modeling of all-dielectric metamaterials," Phys. Rev. B, Vol. 77, 045104, 2008.
20. Smith, D. R., D. C. Vier, T. Koschny, and C. M. Soukoulis, "Electromagnetic parameter retrieval from inhomogeneous metamaterials," Phys. Rev. E, Vol. 71, 036617, 2005.