volume | PIER Journals

Abstract

A novel general technique for treating electrically thin dispersive layer with the finite difference time domain (FDTD) method is introduced. The proposed model is based on the modifying of the node update equations to account for the layer, where the electric and magnetic flux densities are locally averaged in the FDTD grid. Then, based on the characteristics that the complex permittivity and permeability of three kinds of general dispersive media models, i.e., Debye model, Lorentz model, Drude model, the permittivity and permeability can be formulated by rational polynomial fraction in jω, the conversion equation from frequency domain to time domain (i.e., jω replaced by ∂/∂t) and the shift operator method are then applied to obtain the constitutive relation at modified electrical points and the time-domain recursive formula for D and E, B and H available for FDTD computation are obtained. Several numerical examples are presented, indicating that this scheme possesses advantages such as fine generalization, EMS memory and time step saving and good precision.

1. Yang, L. X., D. B. Ge, and B. Wei, "FDTD/TDPO hybrid approach for analysis of the EM scattering of combinative objects," Progress In Electromagnetics Research, Vol. 76, 275-284, 2007.
doi:10.2528/PIER07071206 Google Scholar

2. Wang, M. Y., J. Xu, J.Wu, B.Wei, H.-L. Li, T. Xu, and D.-B. Ge, "FDTD study on wave propagation in layered structures with biaxial anisotropic metamaterials," Progress In Electromagnetics Research, Vol. 81, 253-265, 2008.
doi:10.2528/PIER07122602 Google Scholar

3. Karkkainen, M. K., "FDTD model of electrically thick frequency-dispersive coatings on metals and semiconductors based on surface impedance boundary conditions," IEEE Trans. Antennas Propagat., Vol. 53, 1174-1186, 2005.
doi:10.1109/TAP.2004.842655 Google Scholar

4. Karkkainen, M. K., "FDTD surface impedance model for coated conductors," IEEE Trans. EMC, Vol. 46, 222-233, 2004. Google Scholar

5. Karkkainen, M. K., "Subcell FDTD modeling of electrically thin dispersive layers," IEEE Transactions on MTT, Vol. 51, 1774-1780, 2003.
doi:10.1109/TMTT.2003.812584 Google Scholar

6. Antonini, G. and A. Orlandi, "Time domain modeling of lossy and dispersive thin layers," IEEE Microwave and Wireless Components Letters, Vol. 17, 631-633, 2007.
doi:10.1109/LMWC.2007.903432 Google Scholar

7. Wei, B., D.-B. Ge, and F. Wang, "A general method for FDTD modeling of wave propagation in frequency-dispersive media," Acta Phys. Sin., Vol. 57, 6290-6297, 2008 (in Chinese). Google Scholar

8. Maloney, J. G. and G. S. Smith, "The efficient modeling of thin material sheets in the finite-difference time-domain method," IEEE Trans. Antennas Propagat., Vol. 40, 323-330, 1992.
doi:10.1109/8.135475 Google Scholar

9. Maloney, J. G. and G. S. Smith, "A comparison of methods for modeling electrically thin dielectric and conducting sheets in the finite-difference time-domain (FDTD) method," IEEE Trans. Antennas Propagat., Vol. 41, 690-694, 1993.
doi:10.1109/8.222291 Google Scholar

10. Tirkas, P. A., "Modeling of thin dielectric structures using the finite-difference time-domain technique," IEEE Trans. Antennas Propagat., Vol. 39, 1338-1344, 1991.
doi:10.1109/8.99042 Google Scholar

11. Taflove, A., Advances in Computational Electromagnetics: The FDTD Method, 2nd Ed., Artech House, 2005.
doi:10.2528/PIER07101902

12. Hu, X.-J. and D.-B. Ge, "Study on conformal FDTD for electromagnetic scattering by targets with thin coating," Progress In Electromagnetics Research, Vol. 79, 305-319, 2008.
doi:10.2528/PIER09011702 Google Scholar

13. Hasar, U. C. and O. Simsek, "An accurate complex permittivity method for thin dielectric materials," Progress In Electromagnetics Research, Vol. 91, 123-138, 2009.
doi:10.2528/PIER09011702 Google Scholar

14. Akerson, J. J., M. A. Tassoudji, Y. E. Yang, and J. A. Kong, "Finite difference time domain (FDTD) impedance boundary condition for thin finite conducting sheets," Progress In Electromagnetics Research,, Vol. 31, 1-30, 2001.
doi:10.2528/PIER00070101 Google Scholar

15. Gong, Z. and G.-Q. Zhu, "FDTD analysis of an anisotropically coated missile," Progress In Electromagnetics Research, Vol. 64, 69-80, 2006.
doi:10.2528/PIER06071301 Google Scholar

16. Zheng, H.-X., X.-Q. Sheng, and E. K.-N. Yung, "Computation of scattering from anisotropically coated bodies using conformal FDTD," Progress In Electromagnetics Research, Vol. 35, 287-297, 2002.
doi:10.2528/PIER02030804 Google Scholar

Prof. Bing Wei

Dr. Shi-Quan Zhang

Dr. Yu-hang Dong

Dr. Fei Wang