Macroscopic Visualization of a Radiated Emission Source Using Cylindrically Scanned Electric Field Amplitude Data

Abstract

In order to efficiently mitigate emissions radiated from electrical equipment, emission source visualization methods need to be studied. In this paper, we propose a new macroscopic visualization method based on an optimization process which uses only cylindrically-scanned electric field amplitude data from an EMI test facility as specified by CISPR, and so does not need a special measurement system. The presented method divides the visualization space into three-dimensional rectangular cells, and estimated current values through the optimization process are sorted into each corresponding cell. By displaying the summed value of every cell, the emission source can be visualized. For this study, the spatial resolution was evaluated by computer simulation, with a result of around 0.2 m using a cell size of 0.1 m. With subsequent experimental verification using a comb generator in a semi-anechoic chamber, the visualization deviation was found to be less than 0.1 m in a frequency range of 100 MHz to 800 MHz. When two spherical dipole antennas were used, the deviation was less than 0.15 m. Finally, visualization results from a facsimile unit and a PC as real EUTs were shown and basic applicability of this method demonstrated.