The expansion wave concept, a new way to model mutual coupling in microstrip arrays, applied with a transmission line model

The emphasis in the analysis of microstrip antennas has moved to the use of integral equation models. The reason is that these models are able to analyze almost any configuration with an inherent high accuracy. Their main drawback is the enormous amount of computations to be performed mainly due to the mutual coupling. A lot of research is dedicated to the development of techniques to overcome these limitations. A technique is presented to model the mutual coupling between antenna elements, reducing the amount of computations without losing the accuracy. It is based on the special characteristics of the electromagnetic field in a layered medium. Although the technique is closely related to an integral equation formulation, it is independent of the model used to analyze the isolated antenna element. To prove this statement, we applied the `expansion wave concept´ in combination with a transmission line model. A verification shows that, in this way, high speed is combined with accuracy