Finite Element Model for the Computation of the Transfer Impedance of Cable Shields

The transfer impedance of a cable shield is a parameter that characterizes its shielding effectiveness. To calculate this parameter, we can use analytical or semiempirical approaches but, in this study, the objective is to adapt a general-purpose finite element formulation. The advantage of a numerical method is that it can be applied to a wider variety of situations, where complex geometries and materials may be present. To obtain numerically the transfer impedance, we first express it as a function of the electric field and then we compute the field by means of the finite element method. The only input data required in the process are the geometry and the material properties of the shield. To validate our numerical model, we apply it to a few cable shields and compare the results of the simulations with analytical models and measurements obtained from the literature.