Some Remarks on the Transmission Line Matrix (TLM) Method and Its Application to Transient EM Fields and to EMC Problems

Abstract

Wolfgang J.R. Hoefer has pioneered the Transmission Line Matrix (TLM) method and made it a powerful tool for time-domain modeling of electromagnetic fields. In his scientific work, Wolfgang Hoefer always is placing a strong focus on imagery thinking and geometric and physical understanding of the electromagnetic phenomena. In this contribution, we invite the apt reader to stroll with us through the garden of TLM and would like to share with him some thoughts on the origin of the TLM method and also present some specific applications. We discuss the relation of the TLM method to Christian Huygens’ model of light propagation and show how the TLM method can be deduced on the basis Huygens’ model by application of network theory. We show how the TLM scheme can be embedded in a general discrete time circuit concept. The application of the TLM method to electromagnetic compatibility (EMC) problems is discussed. As a time-domain method, the TLM method is optimally suited to model broadband and transient electromagnetic phenomena and therefore, combining the TLM method with the Integral Equation method yields a powerful tool for the modeling of complex electromagnetic structures separated by large distances in free space. Introducing network models allows the application of correlation matrix methods for the modeling of stochastic fields.