Analysis of Magnetic Field Penetration into a Slotted Rectangular Enclosure

This study examines the penetration of low-frequency magnetic fields into a rectangular enclosure using an analytical approach. The problem of magnetic field penetration into a two-dimensional rectangular enclosure with a slot, subjected to an incident field at an arbitrary angle, is solved using Fourier transform and mode-matching techniques. Vector magnetic potentials are defined to derive the magnetic field in each region, with modal solutions expressed in terms of Fourier series for the slot region. The transverse and normal magnetic field continuity conditions at the slot are applied to compute the modal solution, which is then used to determine the field in all other regions. The study compares the internal magnetic field magnitude as a function of the incident field angle and slot position. To validate the proposed solution, it is compared with the results of a three-dimensional full-wave numerical analysis.