Finite Difference Time Domain Method And Its Application In Electromagnetic Compatibility Analysis

The use of all kinds of electrical devices make up of a complicated electromagnetic environment (EME). Researching the radiation of electrical devices and their work state under complicated environment is an important field of electromagnetic compatibility (EMC) subject. In this paper, the radiation from commonly used devices and their effect caused by extern field from the point of view of field.Computer is used to realize the simulation of EM problem, so methods such as method of moments (MoM) and finite element method (FEM) commonly used to analyze these kinds of problem are introduced briefly. Finite-difference time-domain (FDTD) method is a excellent solution to analyze EMC problem, using it we not only can get the distribution of power density and contour of frequency spectrum of the field radiated by electrical devices but also can research the effect arisen by extern field. It抯 basic theory and relative useful techniques such as program language and CAD technique are presented in detail.Shielding effectiveness (SE) calculation of metal cavity with apertures is a difficult problem. The effect of the shape of apertures and number of holes on shielding effectiveness is analyzed. Radiation from mobile telephone is also studied; some useful charts are given in the paper. In the electromagnetic compatibility analysis at system level, the location and direction of wire will affect the performance of the system. In this paper, radiation from wire is calculated. As an experiment, this article compares the ray tracing method with FDTD in the solution of EME analysis. Couple between two antennas is considered. Using FDTD to calculate the path loss in a room, good results are gained compared with the measurement \and data from the reference. Electromagnetic compatibility problem of communication vehicle, which contains many electrical devices are analyzed with comprehensive consideration.Good agreement between the calculated data using FDTD method and data finin references prove that FDTD is effective method in the analysis of EMC problem; it will he used more widely.