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... https://northwerstknivers.shop/product-category/folding-gentlemans/