Strong formulation of open-space initial boundary-value problems in the form of closed ones for compact waveguide transformers

The outcome of a search for efficient and correct ways for the truncation of the computational domain in direct numerical methods that are used for the electrodynamic analysis of complex waveguide junctions is presented. The relevant mathematical problem is resolved rigorously, both for two-dimensional scalar model problems and for three-dimensional vector problems. We describe briefly only one typical three-dimensional situation. The peculiarities associated with a change to the analysis of other similar three- and two-dimensional vector and scalar problems are also covered.