A SPICE model for near-field transient analysis of ferromagnetic grids

Ferromagnetic grids are becoming more and more popular for electromagnetic shielding applications in avionics, satellite design, and power electronic systems. This paper presents an equivalent homogeneous but anisotropic model of a planar ferromagnetic grid. The nonlinear characteristic and the hysteresis of the material are taken into account. The field source is a low frequency magnetic dipole placed in the proximity of the grid. Both grid and source models are given in the form of multiconductor transmission line (TL) equations. They are solved, in the time domain, by the circuit simulator SPICE.