Frequency dependence of integral-equation macromodel matrices

Andrzej A. Kucharski

One of well-known ways of dealing with problems of computational electromagnetics is decomposing complex situations into simpler ones. In the framework of integral equation/method-of-moments (IE/MoM) solutions, this may be achieved by applying equivalence principles to separate chosen regions of space. Such an attitude leads to so-called domain decomposition methods (DDMs). Recently, the DDM technique has been successfully combined with the fast frequency sweep method, based on asymptotic waveform evaluation (AWE) algorithm. The resulting independently pre-calculated matrices, valid in wide frequency bands, have been named macromodels, by the analogy to macromodels used in differential equation methods like FDTD or FEM.

In this work, integral-equation macromodel (IEM) matrices, previously developed for cavity backed aperture antennas are investigated. The frequency dependence of the matrix elements is shown and discussed, forming the basis for more deep understanding of the combined DDM/AWE method.