Research And Application Of The Subgrid Technology Based On FDTA Method

Finite difference time-domain (FDTD) method is one of the important methods incomputational electromagnetics. The method shows cheerful prospects of rapid development andwidespread application since it’s proposed by Yee in1966. The quantification of space in cells offinite size is a known drawback to the FDTD method. Details smaller than the cell size cannot bemodeled.This paper do research on subgridding technique to overcome this limitation.With the subgirdding technique, part of the FDTD grid is replaced with a finer grid called thesubgrid. This paper studies two different subgirdding techniques, wave equation subgriddingmethod and Huygens subgridding (HSG) method. Few papers have been published on subgriddingin the domestic. In this paper, the two kinds of subgriding techniques in the three dimensional caseare studied in order to make it more widely used in practical problems.In this paper, the theory of FDTD is introduced firstly. Secondly, two subgridding methods aredescribed and Fortran programming language is used to realize the algorithms. At the same time,some experiments are designed to verify the features of subgridding methods. The HSG method hasseveral advantages, such as the ratio of the steps of the grids can be arbitrarily large and thenumerical spurious field resulting from the connection of the grids is quite small. At last, the HSGmethod is applied in the slot problem and wireless channel modeling, and the characteristics of thewireless channel are analyzed.