EFFICIENT TLM DIAKOPTICS FOR SEPARABLE STRUCTURES

An efficient yet rigorous application of diakoptics to TLM simulation of discontinuities in homogeneously filled waveguides is proposed. The method, based on the expansion of the time-domain Green's function in to frequency independent eigenfunctions, leads to a dramatic reduction of the numerical effort when compared to the standard Johns Matrix ap proach. Numerical results show that this new approach provides wide ba nd absorbing boundaries for waveguide problems where several modes (wh ether propagating or evanescent) are present. In this way, the computa tional domain is also reduced to just a small region around the discon tinuity, with the absorbing boundaries placed just a few cells away.