ABSORBING AND CONNECTING BOUNDARY-CONDITIONS FOR THE TLM METHOD

Absorbing and connecting boundary conditions are implemented for the t ransmission-line matrix (TLM) method. The approach is based on an equi valence previously established between the finite-difference-time-doma in (FD-TD) method and the TLM method. Boundary conditions presently us ed for the FD-TD algorithm can be transformed into conditions that can be interfaced with two-and three-dimensional (2D and 3D) TLM schemes. Additional conditions are introduced for 3D-TLM symmetrical condensed node simulations to suppress instabilities caused by spurious modes, inherent to the model, and which are amplified by absorbing boundaries . Numerical results and the comparison with other methods show the goo d performance of the proposed algorithms.