Transmission-line matrix method with irregularly graded space

The paper describes a proposed modification to the transmission-line-matrix method of numerical analysis (TLM). The conventional formulation of this technique uses squares and cubes for space quantisation in two and three dimensions, respectively. This restriction, which is due to the necessity of time synchronism, severely affects the efficiency of the method. The paper introduces a technique in which the propagation space can be irregularly graded according to the nature of the problem under investigation. A new formulation for TLM in the r¿-plane of polar coordinates is also introduced; here the space elements are non-uniform by nature.