Enhancement of Time-Domain Electromagnetic Inverse Method for Modeling Circuits Radiations

To ensure the reliability and safety of the modern electronic systems face of these electromagnetic interference which are becoming more and more important, modeling methods based on the emissions in the near field of these systems are needed. However, the developed methods and in particular the electromagnetic inverse method in the frequency domain have several limitations to model and characterize the systems which emit a nonsinusoidal electromagnetic radiation. To cope with these limitations, in this paper, the electromagnetic inverse method in the time domain has been developed. Using measured near-field cartography above the studied system, the method, based on genetic algorithms, consists in identifying equivalent emitting dipoles. The identification traverses the entire mapping by identifying all sources from the most intense to the lowest source. The proposed method has been validated, first, using calculated cartographies above known dipoles and, second, using measured cartographies above actual dc-dc converters. A very good agreement has been observed between the near magnetic field cartography calculated using the obtained model and that's emitted by the studied system. The proposed method can be used for the identification of equivalent emitting sources of systems excited by nonsinusoidal currents in a widely lowest time as that of the frequency method.