Numerical modelling of transient radiated interferences in time domain by the hybrid ARE method

The novel method of Adapted Radiating Boundaries (ARB) is presented for num erical time domain modelling of transient electromagnetic interference betw een objects separated by the free space. These objects may be of complex sh ape and of compound structure containing various conducting, dielectric and lossy materials. In the ARE-method, only those spatial regions are discret ized, which are occupied by objects. For the numerical modelling of the hel d inside these object regions, the TLM-method is applied. The treatment of the electromagnetic coupling of the objects across the free space is based on the equivalence theorem in the Huygens-Schelkunoff representation. By th is way the self-coupling of the objects as well as the mutual coupling is t reated. The equivalence theorem is taken into account also to obtain adapte d boundaries of the discretized regions by using discrete TLM-Green's funct ions, well adapted to the TLM scheme. The ARE-method is a marching-on-in-ti me method, yielding a fast and stable algorithm. As an example we model the interference of a transient current on a conductor inside a wall with prin ted circuit boards inside a shielding enclosure. The numerical results of t he ARE method are compared with results of the pure TLM method. While the r esults show a very good agreement, the CPU time required for the ARE method is one order of magnitude less than the CPU-time required for the pure TLM method. Copyright (C) 1999 John Wiley & Sons, Ltd.