WAVE-ENVELOPE AND TRANSFORMATION-METHODS FOR FINITE-ELEMENT SOLUTION OF UNBOUNDED ELECTROMAGNETIC-WAVE PROBLEMS

The Wave-Envelope (WE) Method is a technique that has been applied to acoustic problems to model the unbounded domain surrounding an acousti c source. Here it is applied to electromagnetic wave problems. A key f eature of the method is that it uses a change of dependent variable to remove the wave-like qualities of the solution and thereby permits th e use of arbitrarily large elements in the exterior domain. This makes it possible to apply to wave problems some of the techniques develope d for magnetostatics, such as Transformation Methods. These methods ma p the very large exterior domain into a smaller region which is more e asily meshed. The combined Wave-Envelope Transformation Method is appl ied to two time-harmonic electromagnetic wave problems: radiation of a single cylindrical wave function; and scattering of an incident plane wave by a perfectly-conducting circular cylinder. In both cases the n ear-zone electric field is compared to the exact solution, for a range of frequencies.