Numerical solution of scattering of waves by lossy dielectric surfaces using a physics‐based two‐grid method

Abstract

The numerical solution of the scattering of waves by lossy dielectric surfaces often requires a dense surface discretization of many points per wavelength. To reduce the CPU requirements, we have used a physics-based two-grid method (PBTG). In the method, we use two grids: a dense grid and a coarse grid of the usual ten points per wavelength. The method is based on the following two observations: 1) the Green's function of the lossy dielectric is heavily attenuative, and 2) the Green's function of free space is slowly varying on the dense grid. The method is illustrated with Monte Carlo simulations of scattering of waves by random rough surfaces of TE incidence. The examples illustrate the importance of using the dense grid for accurate results, and also the usefulness of PBTG in speeding up the calculations. © 1997 John Wiley & Sons, Inc. Microwave Opt Technol Lett 16: 356–364, 1997.