A new metamaterial topology is proposed, based on dielectric coated spheres. The effect of the coating is an increased negative permittivity and permeability bandwidth compared with the non-coated spheres. The influence of the dimensional parameters is analyzed, and the relation of each of them with the bandwidth is studied. The theoretical results are confirmed by full wave simulations using CST. A combination of the new topology with wires is used to reach an NRI bandwidth of about 23%. To the knowledge of the authors, to date this is the highest bandwidth reported in literature.
2. Shelby, R. A., D. R. Smith, and S. Schultz, "Experimental verification of a negative index of refraction," Science, Vol. 292, 77-79, Apr. 2001.
3. Pendry, J. B., A. J. Holden, D. J. Robbins, and W. J. Stewart, "Magnetism from conductors and enhanced nonlinear phenomena," IEEE Transactions on Microwave Theory and Techniques, Vol. 47, 2075-2084, Nov. 1999.
4. Enkrich, C., M. Wegener, S. Linden, S. Burger, L. Zschiedrich, F. Schmidt, J. F. Zhou, T. Koschny, and C. M. Soukoulis, "Magnetic metamaterials at telecommunication and visible frequencies," Phys. Rev. Lett., Vol. 95, 203901, 2005.
5. Huangfu, J., L. Ran, H. Chen, X. Zhang, K. Chen, T. M. Grzegorczyk, and J. A. Kong, "Experimental confirmation of negative refractive index of a metamaterial composed of Ω-like metallic patterns," Appl. Phys. Lett., Vol. 84, 1537-1539, 2004.
6. Chen, H., L. Ran, J. Huangfu, X. M. Zhang, K. Chen, T. M. Grzegorczyk, and J. A. Kong, "Magnetic properties of S-shaped split-ring resonators," Progress In Electromagnetics Research, Vol. 51, 231-247, 2005.
7. Linden, S., C. Enkrich, M. Wegener, J. Zhou, T. Koschny, and C. M. Soukoulis, "Magnetic response of metamaterials at 100 terahertz," Science, Vol. 306, 1351-1353, Nov. 2004.
8. Bilotti, F., A. Toscano, and L. Vegni, "Design of spiral and multiple split-ring resonators for the realization of miniaturized metamaterial samples," IEEE Transactions on Antennas and Propagation, Vol. 55, 2267, Aug. 2007.
9. Gans, R. and H. Happel, "Zur optik kolloidaler metallÄosungen," Ann. Physik, 277-300, 4th Folge, Bd. 29, 1909.
10. Holloway, C. L., E. F. Kuester, J. Baker-Jarvis, and P. Kabos, "A double negative (DNG) composite medium composed of magnetodielectric spherical particles embedded in a matrix," IEEE Transactions on Antennas and Propagation, Vol. 51, 2603, Oct. 2003.
11. Lewin, L., "The electrical constants of a material loaded with spherical particles," Electrical Engineers --- Part III: Radio and Communication Engineering, Vol. 94, 65-68, Jan. 1947.
12. Vendik, O. G. and M. S. Gashinova, Artificial double negative (DNG) media composed by two different dielectric sphere lattices embedded in a dielectric matrix, 34th European Microwave Conference 2004, Vol. 3, 1209-1212.
13. Jylhä, L., I. Kolmakov, S. Maslovski, and S. Tretyakov, "Modeling of isotropic backward-wave materials composed of resonant spheres," J. Appl. Phys., Vol. 99, 043102, 2006.
14. Sihvola, A., Electromagnetic Mixing Formulas and Applications, IEE Electromagnetic Waves Series, Vol. 47, The Institution of Electrical Engineers, Stevenage, Herts, UK, 1999 .
15. Wheeler, M. S., J. S. Aitchison, and M. Mojahedi, "Coated nonmagnetic spheres with a negative index of refraction at infrared frequencies," Phys. Rev. B, Vol. 73, 045105, 2006.
16. Basilio, L. I., L. K. Warne, W. L. Langston, W. A. Johnson, and M. B. Sinclair, "Microwave-frequency, negative-index metamaterial designs based on degenerate dielectric resonators," IEEE Antennas and Wireless Propagation Letters, Vol. 11, 113-116, Jan. 2012.
17. Kuester, E. F., N. Memic, S. Shen, A. Scher, S. Kim, K. Kumley, and H. Loui, "A negative refractive index metamaterial based on a cubic array of layered nonmagnetic spherical particles ," Progress In Electromagnetics Research B, Vol. 33, 175-202, 2011.
18. Peng, L., L. Ran, H. Chen, H. Zhang, J. A. Kong, and T. M. Grzegorczyk, "Experimental observation of left-handed behavior in an array of standard dielectric resonators," Phys. Rev. Lett., Vol. 98, 157403, 2007.
19. Zhao, Q., L. Kang, B. Du, H. Zhao, Q. Xie, X. Huang, B. Li, J. Zhou, and L. Li, "Experimental demonstration of isotropic negative permeability in a three-dimensional dielectric composite," Phys. Rev. Lett., Vol. 101, 027402, 2008.
20. Cai, X., R. Zhu, and G. Hu, "Experimental study for metamaterials based on dielectric resonators and wire frame," Metamaterials, Vol. 2, 220-226, Dec. 2008.
21. Lepetit, T., É. Akmansoy, and J.-P. Ganne, "Experimental measurement of negative index in an all-dielectric metamaterial," Appl. Phys. Lett., Vol. 95, 121101, 2009.
22. Liu, L., J. Sun, X. Fu, J. Zhou, Q. Zhao, B. Fu, J. Liao, and D. Lippens, "Artificial magnetic properties of dielectric metamaterials in terms of effective circuit model," Progress In Electromagnetics Research, Vol. 16, 159-170, 2011.
23. Yannopapas, V. and A. Moroz, "Negative refractive index metamaterials from inherently non-magnetic materials for deep infrared to terahertz frequency ranges," Journal of Physics: Condensed Matter, Vol. 17, 3717, 2005.
24. Garcia-Etxarri, A., R. Gomez-Medina, L. S. Froufe-Perez, C. Lopez, L. Chantada, F. Sche®old, J. Aizpurua, M. Nieto-Vesperinas, and J. J. Saenz, "Strong magnetic response of submicron Silicon particles in the infrared," Optics Express, Vol. 19, 4815, Mar. 2011.
25. Ahmadi, A. and H. Mosallaei, "All-dielectric metamaterial: Double negative behavior and bandwidth-loss improvement," Antennas and Propagation Society International Symposium, 5527-5530, Jun. 2007.
26. Vendik, I. B., M. A. Odit, and D. S. Kozlov, "3D isotropic metamaterial based on a regular array of resonant dielectric spherical inclusions ," Metamaterials, Vol. 3, 140-147, 2009.
27. Bohren, C. F. and D. R. Huffman, "Absorption and Scattering of Light by Small Particles," Wiley, University of California, Berkeley, 1983.
28. Tserkezis, C., C. Gantzounis, and N. Stefanou, "Collective plasmonic modes in ordered assemblies of metallic nanoshells," Journal of Physics: Condensed Matter, Vol. 20, 075232, 2008.
29. Li, J., G. Sun, and C. T. Chan, "Optical properties of photonic crystals composed of metal-coated spheres," Phys. Rev. B, Vol. 73, 075117, 2006.
30. Pendry, J. B., A. J. Holden, W. J. Stewart, and I. Youngs, "Extremely low frequency plasmons in metallic mesostructures," Phys. Rev. Lett., Vol. 76, 4773-4776, 1996.
31. Pendry, J. B., A. J. Holden, D. J. Robbins, and W. J. Stewart, "Low frequency plasmons in thin-wire structures," Journal of Physics: Condensed Matter, Vol. 10, 4785, 1998.
32. Smith, D. R., S. Schultz, P. Marko·s, and C. M. Soukoulis, "Determination of effective permittivity and permeability of metamaterials from reflection and transmission coefficients," Phys. Rev. B, Vol. 65-195104, 2002.
33. Kim, S., E. F. Kuester, C. L. Holloway, A. D. Scher, and J. Baker-Jarvis, "Boundary effects on the determination of metamaterial parameters from normal incidence reflection and transmission measurements," IEEE Transactions on Antennas and Propagation, Vol. 59, 2226, Jun. 2011.
34. Kim, S., E. F. Kuester, C. L. Holloway, A. D. Scher, and J. Baker-Jarvis, "Effective material property extraction of a metamaterial by taking boundary effects into account at TE/TM polarized incidence," Progress In Electromagnetics Research B, Vol. 36, 1-33, 2012.
35. Chen, X., T. M. Grzegorczyk, B. Wu, J. Pacheco, and J. A. Kong, "Robust method to retrieve the constitutive effective parameters of metamaterials," Phys. Rev. E, Vol. 70, 016608, 2004.
36. 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.
37. Vasylchenko, A., Y. Schols, W. De Raedt, and G. A. E. Vandenbosch, "Quality assessment of computational techniques and software tools for planar antenna analysis," IEEE Antennas Propagat. Magazine, Vol. 51, No. 1, 23-38, Feb. 2009.
38. He, X., Y. Wang, J. Mei, T. Gui, and J. Yin, "Three-dimensional surface current loops in broadband responsive negative refractive metamaterial with isotropy," Chinese Physics B, Vol. 21, 044101, 2012.