In this paper we numerically study the propagation of surface waves guided by a metal-backed dielectric slab with biperiodic metallizations on its surface. Such structures are electromagnetic absorbing screens when the dielectric slab is lossy. In this paper, the surface waves are characterizedb y their longitudinal andtransv erse wave numbers, which are deduced from the complex pole locations of the reflection coefficient of the screens. The reflection coefficients can be obtainedwith a moment method. These reflection coefficients are generalizedto complex incident wave numbers. The poles are isolated in the complex plane with the help of the argument principle and are calculatedwith a numerical methodbasedon MÂ¨uller's algorithm. Then the parametric study of the wave numbers of the surface waves shows that the absorption of an electromagnetic wave by the screens at normal incidence is due to a resonance of the real part of the transverse wave number of the excitedsurface wave. We also show that there exists a Brewster incidence angle for the absorbing screens with suitable metallization array dimensions. This Brewster angle appears when the pole crosses the branch cut of the two-sheetedRiemann space of the reflection coefficient.
2. Goubau, G., "Surface waves andtheir application to transmission lines," Journal of Applied Physics, Vol. 21, No. 11, 1119-1128, 1950.
3. Attwood, S. S., "Surface wave propagation over a coated plane conductor," J. Applied Physics, Vol. 22, 504-509, 1951.
4. Ling, R. T., J. D. Scoller, and P. Ya. Ufimtsev, "The propagation andexcitation of surface waves in an absorbing layer," Progress In Electromagnetic Research, Vol. Vol. 19, 49-91, 1998.
5. Felsen, L. B. andN. Marcuvitz, Radiation and Scattering of Waves, Prentice-Hall, Inc., 1973.
6. Jacobsen, J., "Analytical, numerical, andexp erimental investigation of guided waves on a periodically strip-loaded dielectric slab," IEEE Transactions on Antennas and Propagation, Vol. AP-18, No. 3, 379-388, 1970.
7. Berginc, G., C. Bourrely, C. Ordenovic, and B. Torresani, "A numerical study of absorption by multilayered biperiodic structure," Progress in Electromagnetic Research, Vol. Vol. 19, 199-222, 1998.
8. Terracher, F. and G. Berginc, "A broadbandd ielectric microwave absorber with periodic metallizations," Journal of Electromagnetic Waves and Applications, Vol. 13, 1725-1741, 1999.
9. Felsen, L. B. and N. Marcuvitz, Radiation and Scattering of Waves, 5-6, Chapter 5.
10. Chabat, B., Introduction `a l'Analyse Complexe, Tome 1, Fonctions d'une variable, Mir and Moscou (eds.), 1990.
11. Burke, J. J., "Propagation constants of resonant waves on homogeneous, isotropic slab waveguides," Applied Optics, Vol. 9, No. 11, 2444-2452, 1970.
12. Richmond, J. H., L. Peters, Jr., and R. A. Hill, "Surface waves on a lossy planar ferrite slab," IEEE Transactions on Antennas and Propagation, Vol. AP-35, No. 7, 802-808, 1987.
13. Terracher, F. andG. Berginc, Thin electromagnetic absorber using frequency selective surfaces, Proc.2000 IEEE AP-S International Symposium, 846-849.
14. Sha, Y., K. A. Jose, C. P. Neo, and andV. K. Varadan, "Experimental investigation s of microwave absorber with FSS embedded in carbon fiber composite," Microwave and Optical Technology Letters, Vol. 32, No. 4, 2002.