New Oblique Thin Wire Formalism in the FDTD Method
Résumé
n the FDTD method, the Cartesian meshing is a critical point for conforming structures and small geometries. For thin wire formalism, one cumulates small section with a problem of conforming to the Yee's cell and fast variation of both looping magnetic field and radial electric field close to the wire. Among all previous thin wire published models, only Holland's approach [1] has evolved toward inclined wires. Hence the works of Ledfelt [2] and Edelvik [3] show that it is possible to have a wire's behaviour independent of its location in the Yee's cell or its obliquity. Our new approach compared to [3] is justified by the necessity to deal with a junction between several oblique wires. Indeed [3] is not extended for multiwire junction because the coupling between the wire current and the electrical field uses a cylinder-shaped stencil with a section superior to the FDTD cell size and so it is too difficult to suit correctly to a junction with more than two wires. To avoid this problem, we propose a technique where the coupling between the wire and the FDTD meshing is limited to only the cells that contain a part of the wire.