A 2D-transmission line model for the EM field estimation inside enclosures with apertures

The development of efficient phenomenological models which give accurate estimates for the coupling of electromagnetic energy through apertures and into enclosures is important for the EMC design of almost all electronic subsystems. It has been previously shown that a simple analytical transmission line formulation gives good predictions of the dominant mode TE₁₀ as well as higher-order modes TE_m0 inside a rectangular enclosure with apertures. In this work the model is extended to include a two-dimensional set of transverse electric modes TE_mn in the transmission line (TL) model. The rectangular enclosure with aperture is represented as a intersection of two orthogonal transmission lines, one for each set of transverse electric modes. The model remains very simple and computationally efficient. The finite difference time-domain (FDTD) method is used to validate the results.