Level Predictions and Its Reduction Method of Electromagnetic Fields Due to Electrostatic Discharge Causing Electromagnetic Interference to Information Communication Equipment

带电金属间静电放电产生的瞬态电磁场具有高达微波区的宽带频谱，对高科技信息设备造成严重的故障。这种静电场受到金属存在的显著影响，而这种影响尚未得到很好的理解。该研究项目的首席研究员之前开发了一种预测静电放电场的方法，该方法使用时域有限差分（FDTD）技术，结合从Rompe-Weizel火花电阻公式中导出的火花电流，该方法表明，金属的存在根据其尺寸增强了电场水平。本课题的研究目的是在上述研究成果的基础上开发ESD场的计算机仿真代码，并提供一种降低ESD场电磁干扰的技术。在这个研究项目中获得的结果概要如下…考虑了两个球形金属之间的火花模型。利用FDED方法计算了金属球间火花产生的电磁场。研究了两种类型的火花隙激励，求出了关于静电放电场的Maxwell方程，用于FDED计算算法。激励源为火花电流和火花电压，两者均由火花电阻的Rompe-Weiziel公式以封闭形式得到。结果发现，电流激励无法计算出ESD发生前包含静电场分量的电场波形，而电压激励建模通过宽带磁场测量得到，两种激励计算的结果吻合较好。通过对金属球间火花磁场波形的宽带测量，验证了激励模型的有效性。目前，我们正在构建一种新的时域有限差分算法，该算法能够预测任意形状的带电金属之间的火花产生的静电放电场，并研究铁氧体铁芯附着对降低带电金属产生的静电放电场的影响。少

The transient electromagnetic fields due to electrostatic discharge (ESD) between charged metals have wide-band frequency spectra up to the microwave region, which cause serious malfunction to high-tech information devices. Such ESD fields are significantly affected by the presence of the metal, whereas the effect is not well understood. The head investigator of this research project previously developed a method for predicting the ESD fields using the finite-difference time-domain (FDTD) technique in conjunction with a spark current theoretically derived from the Rompe-Weizel spark resistance formula, which showed that the presence of the metal enhance the field level according to its dimension. The purpose of this research project is to develop computer simulation codes for the ESD fields based on the above findings, and is also to provide a technique for reducing the electromagnetic interference due to ESD fields. The outline of the results obtained in this research project was as f … More ollows. A spark model between two spherical metals being spaced at a gap was considered. The FDED method was used to compute the electromagnetic fields due to the spark between the metal spheres. Two types of spark gap excitation were investigated to differentiate the Maxwell equations concerning the ESD fields for the FDED computation algorithm. The excitation sources were a spark current and s spark voltage that were both obtained in closed forms from the Rompe-Weiziel formula for a spark resistance. As a result, we found that the current excitation is unable to compute the electric field waveform including the electrostatic field component before the ESD happens, while the voltage excitation modeling was confirmed by wide-band measurement of the magnetic field, good agreement was observed between the results that wave computed by the both excitations. The validity for the excitation modeling was confirmed by wide-band measurement of the magnetic field waveform due to a spark between metal balls. At present, we are constructing a new FDTD algorithm which enables us to predict the ESD fields caused by the spark between charged metals having arbitrary shapes, and also examine the effects of ferrite core attachment in reducing the ESD fields by charged metals. Less