Probe Design and Source Reconstruction for Near-Field Scanning and Modeling

This paper elaborates the near-field scanning and modeling technique developed for electromagnetic interference (EMI) analysis. The technique has been increasingly deployed in many R&D labs of universities and testing centers of industry companies due to its advantages in terms of time and cost, comparing with conventional EMI measurement methods. The major research works related to the near-field scanning and modeling are probe design and source reconstruction method (SRM). In this article, the working principle of electric and magnetic probes are firstly introduced. Probe parameters including calibration factor, electric center, sensitivity, spatial resolution and bandwidth are discussed. Next, the equivalent radiation source modeling approach is presented. Through SRM, a complex and unknown EMI source is substituted with the simplified equivalent radiation source based on the electromagnetic fields measured by magnetic and/or electric probes. The phaseless SRM is thereafter discussed for addressing the limitations in conventional SRM and its applications prove that the near-field scanning and modeling technique can effectively predict EMI far-field radiation and near-field coupling.