ABSTRACT
Transmission-line modeling (TLM), otherwise known as the transmission-line-matrix method, is a numerical technique for solving field problems using circuit equivalent. It is based on the equivalence between Maxwell's equations and the equations for voltages and currents on a mesh of continuous two-wire transmission lines. The main feature of this method is the simplicity of formulation and programming for a wide range of applications. The TLM method involves dividing the solution region into a rectangular mesh of transmission lines. Junctions are formed where the lines cross forming impedance discontinuities. A comparison between the transmission-line equations and Maxwell's equations allows equivalences to be drawn between voltages and currents on the lines and electromagnetic fields in the solution region. The method is limited only by the amount of memory storage required, which depends on the complexity of the TLM mesh. The TLM method is suitable for nonlinear or inhomogeneous problems since any variation of material properties may be updated at each time step.
