Calculation of induced field and surface current due to multiple internal magnetic dipoles inside a rectangular cavity

Abstract

Summary form only given. The EMC problems which come into question from a rectangular enclosure excited by internal magnetic dipole sources are studied. Dyadic Green's functions provide a powerful tool for the description of the interaction between the sources and the enclosure. ICs and PCB tracks are modeled in terms of small magnetic dipoles and finite length square loops respectively. The points of interest are restricted to the cavity walls which are assumed to be perfect conductors. Small sources like ICs have a magnetic dipole moment which can be decomposed in three normal components for all directions. It is shown that each one of the cartesian components reacts with the cavity in a unique but predictable manner. Square loops with different geometries are also examined. Using the corresponding dyadic Green's function the electric field and surface current density are determined. The numerical results evaluated for some representative cases are graphically compared. The effect of multiple sources can be summed using the principle of superposition. Numerical results are normalized. Finally, conclusions are presented and some simple rules, which can be applied in PCB design are found.