Abstract
In this paper we present a time domain formulation to compute electromagnetic fields in any homogeneous media out of a bounded domain. Main result is given by the establishment of a transport formula, which accuracy is quantified by the ratio of two length quantities. Moreover this provides a fine, simple and adaptive way to compute electromagnetic fields from given currents lying onto a non-convex polyhedral surface. Illustrations of this method and comparison with classical Near-To-Far technique are given.