The microwave transmission of hexagonal arrays consisting of patches of equilateral aluminium triangles has been experimentally studied as a function of metal occupancy (triangle size). As one would expect, at low frequencies the microwave transmission drops on passing through the connectivity threshold (50%) when the disconnected hexagonal array of metal triangles switches to a disconnected hexagonal array of equilateral holes. However, for higher frequencies resonant phenomena cause a complete reversal in this behaviour such that the transmission, on passing through the connectivity threshold, increases substantially.
2. Martin-Moreno, L., F. J. Garcia-Vidal, H. J. Lezec, K. M. Pellerin, T. Thio, J. B. Pendry, and T. W. Ebbesen, "Theory of extraordinary optical transmission through subwavelength hole arrays," Phys. Rev. Lett., Vol. 86, 1114, 2001.
3. Genet, C. and T. W. Ebbesen, "Light in tiny holes," Nature, Vol. 445, 39, 2007.
4. Antonets, I. V., L. N. Kotov, S. V. Nekipelov, and E. N. Kar- pushov, "Conducting and reflecting properties of thin metal films," Tech. Phys., Vol. 49, 1496, 2004.
5. Kelly, R. J., M. J. Lockyear, J. R. Suckling, J. R. Sambles, and C. R. Lawrence, "Enhanced microwave transmission through a patterned metal film," Appl. Phys. Lett., Vol. 90, 223506, 2007.
6. Hansen, R. C. and W. T. Pawlewicz, "Effective conductivity and microwave reflectivity of thin metallic films," IEEE Trans. Microw. Theory Tech., Vol. 30, 2064, 1982.
7. Lagarkov, A. N., K. N. Rozanov, A. K. Sarychev, and N. A. Si- mona, "Experimental and theoretical study of metal-dielectric percolating films at microwaves," Physica A, Vol. 241, 199, 1997.
8. Kim, J. H. and P. J. Moyer, "Transmission characteristics of metallic equilateral triangular nanohole arrays," Appl. Phys. Lett., Vol. 89, 121106, 2006.
9. Bethe, H. A., "Theory of diffraction by small holes," Phys. Rev., Vol. 66, 163, 1944.
10. Ghaemi, H. F., T. Thio, D. E. Grupp, T. W. Ebbesen, and H. J. Lezec, "Surface plasmons enhance optical transmission through subwavelength holes," Phys. Rev. B, Vol. 58, 6779, 1998.
11. Popov, E., M. Neviere, S. Enoch, and R. Reinisch, "Theory of light transmission through subwavelength periodic hole arrays," Phys. Rev. B, Vol. 62, 16100, 2000.
12. Popov, E., S. Enoch, G. Tayeb, M. Neviere, B. Gralak, and N. Bonod, "Enhanced transmission due to nonplasmon resonances in one-and two-dimensional gratings," Appl. Opt., Vol. 43, 999, 2004.
13. Avrutsky, I., Y. Zhao, and V. Kochergin, "Surface-plasmon-assisted resonant tunneling of light through a periodically corrugated thin metal film," Opt. Lett., Vol. 25, 595, 2000.
14. Grupp, D. E., H. J. Lezec, T. W. Ebbesen, K. M. Pellerin, and T. Thio, "Fundamental role of metal surface in enhanced transmission through subwavelength apertures," Appl. Phys. Lett., Vol. 77, 1569, 2000.
15. Thio, T., H. F. Ghaemi, H. J. Lezec, P. A. Wolff, and T. W. Ebbe- sen, "Surface-plasmon-enhanced transmission through hole arrays in Cr films," Opt. Soc. Am. B, Vol. 16, 1743, 1999.
16. Degiron, A., H. J. Lezec, W. L. Barnes, and T. W. Ebbesen, "Effect of hole depth on enhanced light transmission through subwavelength hole arrays," Appl. Phys. Lett., Vol. 81, 4327, 2002.
17. Papasimakis, N., V. A. Fedotov, A. S. Schwanecke, N. I. Zheludev, and F. J. Garia de Abajo, "Enhanced microwave transmission through quasicrystal hole arrays," Appl. Phys. Lett., Vol. 91, 081503, 2007.
18. Munk, B. A., Frequency Selective Surfaces: Theory and Design, Wiley, New York, 2000.
19. Ulrich, R., "Far-infrared properties of metallic mesh and its complementary structure," Infrared Phys., Vol. 7, 37, 1967.
20. Whitbourn, L. B. and R. C. Compton, "Equivalent-circuit formulas for metal grid reflectors at a dielectric boundary," Appl. Opt., Vol. 24, 217, 1985.
21. Dawes, D. H., M. C. McPhedran, and L. B. Whitbourn, "Thin capacitive meshes on a dielectric boundary: Theory and experiment," Appl. Opt., Vol. 28, 3498, 1989.
22. Edmunds, J. D., A. P. Hibbins, J. R. Sambles, and I. J. Youngs, "Resonantly inverted microwave transmissivity threshold of metal grids," New Journal of Physics, Vol. 12, 063007, 2010.
23. Babinet, M. and Memoires d'optique meteorologique, Comptes Rendus de l' Academie des Sciences, Vol. 4, 638, 1837.
24., , Finite Element Modelling: HFSSTM, Ansoft Corporation, Pittsburgh, CA, USA..