A magnetized thin layer mounted on a PEC surface is considered as an alternative for an absorbing layer. The magnetic material is modeled with the Landau-Lifshitz-Gilbert equation, with a lateral static magnetization having a periodic variation along one lateral direction. The scattering problem is solved by means of an expansion into Floquet-modes, a propagator formalism and wavesplitting. Numerical results are presented, and for parameter values close to the typical values for ferro- or ferrimagnetic media, reflection coefficients below -20 dB can be achieved for the fundamental mode over the frequency range 1-4 GHz, for both polarizations. It is found that the periodicity of the medium makes the reflection properties for the fundamental mode almost independent of the azimuthal direction of incidence, for both normally and obliquely incident waves.
2. Iakubov, I., A. Lagarkov, S. Maklakov, A. Osipov, K. Rozanov, I. Ryzhikov, and S. Starostenko, "Microwave permeability of laminates with thin Fe-based films," J. Magn. Magn. Mater., Vol. 272, 2004.
3. Rozanov, K., I. Iakubov, A. Lagarkov, S. Maklakov, A. Osipov, D. Petrov, I. Ryzhikov, M. V. Sedova, and S. Starostenko, Laminates of thin ferromagnetic films for microwave applications, The Sixth International Kharkov Symposium, Vol. 1, 168-173, 2007.
4. Gilbert, T. L., "A phenomenological theory of damping in ferromagnetic materials," IEEE Trans. Magnetics, Vol. 40, 3443-3449, 2004.
5. Acher, O., P. L. Gourrierec, G. Perrin, P. Baclet, and O. Roblin, "Demonstration of anisotropic composites with tuneable microwave permeability manufactured from ferromagnetic thin films," IEEE Trans. Microwave Theory Tech., Vol. 44, 674-684, 1996.
6. Ramprecht, J. and D. Sjoberg, "Biased magnetic materials in RAM applications," Progress In Electromagnetics Research, Vol. 75, 85-117, 2007.
7. Huo, S., J. Bishop, J. Tucker, W. Rainforth, and H. Davies, "Simulation of 3-D micromagnetic structures in thin iron platelet," IEEE Trans. Magnetics, Vol. 33, 4170-4172, 1997.
8. Bagneres, A., "Three-dimensional numerical simulations of stripe chopping in a magnetic perpendicular material," IEEE Trans. Magnetics, Vol. 35, 4318-4325, 1999.
9. Redjdal, M., A. Kakay, M. Ruane, and F. Humphrey, "Cross-tie walls in thin permalloy films," IEEE Trans. Magnetics, Vol. 38, 2471-2473, 2002.
10. Steyskal, H., J. Ramprecht, and H. Holter, "Spiral elements for broad-band phased arrays," IEEE Trans. Antennas Propagat., Vol. 53, No. 8, 2558-2562, 2005.
11. Landau, L. D. and E. M. Lifshitz, "On the theory of the dispersion of magnetic permeability in ferromagnetic bodies," Physik. Z. Sowjetunion, Vol. 8, 153-169, 1935.
12. Landau, L. D. and E. M. Lifshitz, "On the theory of the dispersion of magnetic permeability in ferromagnetic bodies," Collected Papers of L. D. Landau, D. Ter Haar (ed.), 101-114, Reprinted by Gordon and Breach, Science Publishers, 1965.
13. Kittel, C., Introduction to Solid State Physics, 7th Ed., John Wiley & Sons, NewY ork, 1996.
14. Brown, W. F., Micromagnetics, Interscience Publishers, New York, 1963.
15. d’Aquino, M., "Nonlinear magnetization dynamics in thin-films and nanoparticles," Ph.D. thesis, Universita degli studi di Napoli ``Federico II", Facolta di Ingegneria, 2004.
16. Pozar, D. M., Microwave Engineering, 3rd Ed., John Wiley & Sons, New York, 2005.
17. Forslund, O. and S. He, "Electromagnetic scattering from an inhomogeneous grating using a wave-splitting approach," Progress In Electromagnetics Research, Vol. 19, 147-171, 1998.
18. Rikte, S., G. Kristensson, and M. Andersson, "Propagation in bianisotropic media-reflection and transmission," IEE Proc. Microwaves, Antennas and Propagation, Vol. 148, No. 1, 29-36, 2001.
19. Kristensson, G., "Homogenization of corrugated interfaces in electromagnetics," Progress In Electromagnetics Research, Vol. 55, 1-31, 2005.