The determination of noise sources of radiated electromagnetic noise is the first task that needs to be addressed when an electromagnetic compatibility (EMC) problem appears. Broadband noise sources are more difficult to identify, particularly when similar switching frequencies are used by different sources. Four techniques for the fast determination of broadband electromagnetic noise sources in complex equipment are proposed. All the four techniques make use of one-port measurements conducted in near and far field in different time instants, avoiding unwanted effects of the near-field measurement equipment on the far-field distribution. Two techniques are based on modulation frequency analysis, a technique that was recently introduced in EMC. The remaining two techniques make use of the cross-correlation with the time-dependent high-frequency components in far field. Two of the four techniques require only low-frequency measurements in near field and are particularly suitable for high power equipment. The proposed techniques are validated by measurements.

中文翻译：

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通过单端口测量确定宽带电磁噪声源的标量匹配指数


当出现电磁兼容性（EMC）问题时，首先需要解决的就是辐射电磁噪声噪声源的确定。宽带噪声源更难以识别，特别是当不同源使用相似的开关频率时。提出了四种快速确定复杂设备中宽带电磁噪声源的技术。所有四种技术都利用在不同时刻在近场和远场进行的单端口测量，避免了近场测量设备对远场分布的不良影响。有两种技术基于调制频率分析，这是最近在 EMC 中引入的一种技术。其余两种技术利用与远场中随时间变化的高频分量的互相关。四种技术中的两种仅需要近场低频测量，特别适合高功率设备。所提出的技术通过测量得到验证。