A Fast and Efficient Analytical Modeling Approach for External Electromagnetic Field Coupling to Transmission Lines in a Metallic Enclosure

A fast and efficient analytical approach based on the extended Baum-Liu-Tesche (BLT) equation is proposed in this paper to evaluate the external electromagnetic field coupling to transmission lines (TLs) loaded in a metallic enclosure with apertures. The scattering matrix to describe the aperture coupling characteristics required in the BLT equation is effectively derived based on the equivalent circuit theory. The analytical modeling function for calculating internal modal fields coupling to TLs is investigated and developed. Thus, the extended BLT equation can be directly employed in the assessment of current induced at the loads of TLs in the enclosure, which is illuminated by external electromagnetic fields. Via different case studies, the results calculated using the proposed analytical approach have been validated and have been in a good agreement with those simulated by numerical methods. The computational efficiency, in terms of time and memory, has also been improved much for the electromagnetic interference problems.