Treatment of arbitrarily-orientated multiwire bundles and terminated multiwire transmission lines in FDTD method

The finite-difference time-domain (FDTD) method is extremely versatile and widely used but there still remain structures in which the method encounters serious difficulties. One such situation is the analysis of bundles of closely spaced wires which are not parallel to the FDTD mesh. Similar problems are encountered in the analysis of multiconductor transmission lines such as PCB tracks. Recent research has yielded methods for treating single wires, orientated at an angle to the FDTD mesh, and for treating multiwire bundles which are aligned with the mesh, but not for both situations at once. In the paper, an enhanced method is presented which allows the treatment of wire bundles, including those which are arbitrarily orientated with respect to the mesh and those which may also be terminated with lumped components. Results are provided that show the consistency and accuracy of the proposed technique