In order to carry out near-field scans of printed circuit boards for EMC investigations, knowledge of the electric and magnetic fields above various calibration boards is necessary. The transient solver from CST MICROWAVE STUDIO® is therefore employed to calculate the near-field patterns on a scanning plane above various microstrip structures. After a spatial 2D-Fourier-transformation, the field values and the measured probe output signals are used to determine the field probe’s receiving characteristics. The results of this calibration process are then verified by applying them on further field measurements with the probe above another microstrip structure and comparing the obtained field strengths with respective simulations again. To obtain a high spatial field resolution, roughly 2.5 million meshcells are used. The frequency band of interest extends from 1MHz up to 3GHz so that great importance is attached to sufficient energy decay.
Matthias Spang, University Erlangen-Nuremberg