The Analysis Of Typical Electromagnetic Compatibility Problems With FDTD

In this thesis, the application of finite-difference time-domain method (FDTD) to the numerical computation of some typical electromagnetic compatibility (EMC) problems is comprehensively studied. Two parts: the computation on the shielding effect (SE) of the enclosure with apertures and the numerical analysis of the radiated electromagnetic fields of heat sinks on some electric devices are included.The basic theories of the FDTD method are reviewed at the first part of the paper. One of the absorbing boundary conditions, the perfectly matched layer is investigated, its formulas and parameters and some problems that should be noticed are confirmed. The main types of the source excitation are presented, and several commonly used simulation methods are compared. The non-uniform FDTD are studied and the corresponding program is achieved. As well the transformation from near zone to far zone is discussed, especially in the time domain, and is applied in computation of the radiated characteristic of heat sink.Based on the theories of FDTD method, the Fortran computer software are worked out and applied to compute the corresponding SE of the enclosure with apertures of different shape,size and number. Numerical results are achieved and analyzed. Finally, this paper maps out the radiation patterns from a heat sink and explains how different dimensions of the heat sink affect this radiation.