Transmission Line Method And Its Application In Electromagnetic Field Computation In Inhomogeneous Medium

Generally, it is very complex to describe the propagation of the electromagnetic wave in inhomogeneous medium, so we have to turn to the numerical simulation, besides the models of regular boundaries which can be described analytically. At present, the common numerical methods are finite difference, finite element , boundary element, integration equation and transmission line method. Transmission line method (TLM) is a numerical computing method for the electromagnetic field which based on the Huygens' principle. This paper gives the fundamental principles, algorithm and program of TLM. Through comparing of the results of the numerical computing, the following conclusions are drawn:1.) Using TLM to compute electromagnetic field, the physical concept is clear and it is easy to program. The code for TLM can be used for different fields with lesser modification of the corresponding codes.2.) Computes the static electric field in homogeneous medium with TLM and finite difference method respectively. And the results show that in the same discrete cell scale, the result computed by TLM is more consistent with the analytical result than that of finite difference.3.) Computes the electric field generated by point source in inhomogeneous medium with TLM and compares the results with the analytical outcome. The comparison suggests that it is feasible to compute electric field in inhomogeneous medium.4.) It is pointed out that the disadvantage of the TLM is its cost of more memory and run time.