Research on Evaluating Noise Location with High Resolution by Field-Scanning on Closed Surface

本研究针对电子电气设备中影响其他设备性能并造成严重干扰的辐射源，建立了高分辨率的辐射源位置估计方法。首先，研究了一种确定球展开模幂级数系数的方法，以获得高分辨率，特别是在低频下。研究了阵元间互耦对分辨力的影响，利用MUSIC算法获得了高分辨力的源位置信息，然后利用改进的平面扫描技术对印刷电路板上的干扰源进行了估计，最后利用该方法对印刷电路板上的干扰源进行了估计，得到了干扰源的位置信息。提出了一种利用调制散射元件测量电磁源辐射方向图的方法。建立了可同时测量多点电磁波振幅的测量系统，并发展了不干扰电磁源上电流分布的近场测量方法。该方法可以准确地测量噪声源产生的干扰电磁波的幅值。实验结果表明了该方法的有效性。

In this research, methods to estimate the location of the source with high resolution have been established to find the undesired radiation sources in the electrical and electronic devices which affect the performance of the other devices and cause the serious interference problem.First, a method to determine the coefficient of power series of the spherical expansion modes has been investigated to obtain a high resolution especially at low frequency. The effect of the mutual coupling between the array elements on the resolution has also been studied to obtain the information on source location with high resolution by using the MUSIC algorithm.Next, the sources of undesired radiation from a printed circuit board have been estimated by using the improved planar scanning technique.Then, a method of measuring the radiation pattern of the electromagnetic source has been proposed by using the modulated scattering elements. The measurement system has been established which can be used to measure the amplitude of the electromagnetic wave in several points simultaneously.Moreover, the near field measurement without disturbing the current distribution on the electromagnetic source has been developed. The amplitude of the undesired electromagnetic wave from the noise sources can be accurately measured by using this method. The experiment has been performed to show the effectiveness of the method.