Modelling of Arbitrary Slot Structures Using Transmission Line Matrix (TLM) Method

Techniques to model geometrically tiny features, such us thin slots, hatches, seams and gaskets, in an otherwise large three-dimensional space, are presented. The modelling is achieved by introducing appropriate compact models into the transmission line matrix (TLM) time-domain method. Such an extended TLM method allows for accurate EMC modelling of complex devices with geometrically small features without increasing the computer requirements. The method is validated by comparison to the results obtained with an extremely fine mesh using traditional TLM. The application of an arbitrary slot model in evaluating the shielding effectiveness of different seam shapes is presented.