Performance study of one-way absorbing boundary equations in 3D TLM for dispersive guiding structures

Several absorbing boundary conditions (ABCs) based on one-way wave equations (mostly applied to the finite-difference-time-domain method) have been studied and adapted for the 3D symmetrical condensed node analysis of guiding structures. The ABC based on perfect absorption of waves at two incident angles has given superior results when compared to other absorbing boundaries. Reflections less than 2% over a large frequency spectrum have been obtained for dispersive structures like microstrip and finlines. These excellent ABCs can considerably reduce the computational domain, thus making possible the 3D TLM (transmission line matrix) analysis of planar and quasi-planar structures with moderate computer resources.<>