AUTOMATIC AND EFFICIENT SURFACE FDTD MESH GENERATION FOR ANALYSIS OF EM SCATTERING AND RADIATION

摘要

The finite difference time domain (FDTD) method has found very wide applications in the analysis of electromagnetic scattering and radiation. The first and most important issue of the FDTD modeling is to decompose a computation space, containing a given geometry, into FDTD unit cells. There are a few dedicated mesh generators which could discretize the space into cells for general analysis. However, among FDTD applications, a large portion of them deal with objects structured primarily with conducting and/or thin-dielectric plates, such as a conducting sphere or cube, a cavity, an airplane, etc. The mesh data necessary to input are those of node indices and material parameters on the object surface. Consequently geometry modeling is essentially to generate FDTD cells on the surfaces. For this purpose, a simple and effective algorithm capable of on- surface FDTD mesh generation is introduced based on a ray-tracing method. The algorithm presumes that the input geometry is described in polygons and lines which are often approximations of smooth surfaces and thin wires. In output, the algorithm decomposes automatically the polygons and lines into on-surface cells compatible with, and readable by, an FDTD solver. The algorithm has been coded in programs allowing effective and automatic generation of surface cells on various high- or low-end computer platforms. [Vol. 9, No. 2 (1994), pp 162-169]