The transmission line matrix method applied to microstrip antennas

The transmission-line matrix (TLM) method combines Maxwell´s equations and propagation equations in transmission lines forming a three-dimensional network with uniform or nonuniform mesh. It simulates wave propagation in bounded space, describing the transient response at each point. Application of the principle of causality or introduction of absorbent wells allows the extension of the TLM method to open structures. The method was tested on linear wire antennas and then successfully applied to microstrip antennas. Despite the relatively cumbersome numerical computation involved, the method is quite advantageous for complex geometries (limitation of the ground plane or substrate, excitation by slots, or coupling).<>