EM emissions induced by a DC/DC power converter: First experiments on a laboratory system

This paper deals with the emissions induced by a power converter. The final aim is to achieve an optimal design of a power converter printed circuit board (PCB) in the early stage of simulation. This study is focused on a well known Buck converter which operates at a frequency around 1MHz. The load loop was performed of exaggerated dimensions to highlight the problem of radiation and to allow an analysis in detail. Taken into account the frequency and the structure of the converter, this first approach is focused on magnetic field. In order to evaluate the near field probe effects on the measurements results, the system `converter-probe' is modeled using 3-D software (CST MWS) and then, the electromagnetic field radiated by the power converter is calculated and the results are compared with measurements. Two probes are studied, an industrial one and another made in laboratory. The comparison of simulations and measurements results are presented in order to evaluate the emissions induced by the converter and to study the influence of the probe in the measurement.