Low-Frequency Multilayered Magnetic Shielding of Circular Loops

An efficient and reliable analytical approach for calculating the low-frequency magnetic shielding effectiveness of multilayered structures in a source of current loops is presented. A two-dimensional analysis is performed without limiting the number and location of both source wire loops and shielding layers. By means of a transfer function, that represents the shield in the spectral Hankel transform domain, the quasistatic shielded magnetic field is quickly obtained from the source field. The transfer function depends on the geometry and material properties of shielding layers only. The comparison between the obtained results and FEM analysis shows a good agreement in all examined cases.