New Oblique Thin Wire Formalism in the FDTD Method With Multiwire Junctions

A new oblique thin wire formalism based on Holland's approach is proposed in the FDTD method. The principal achievement of this new formalism is to enable us to model a junction correctly between several oblique wires. To this end, an important criterion is proposed: the continuity of the current traces in the grid must be maintained at each node of the Yee cell that contains a part of one or several wires. This condition prevents undamped parasite oscillations on the wire current responses. In addition, our approach offers versatility in its usage. First the extremities of the wire can be placed freely in a Yee cell. Second it operates in lossy medium and finally, the sensitivity of the wire is minimized when inclined or shifted. With regards to this last point, the in-cell inductance of a wire segment is formulated to take account of the segment position and its obliquity in the Yee cell.