In the potential-current representation, transmission-line parameters in the Transmission-Line Super Theory (TLST) do not have a direct physical meaning – they are gauge dependent. The transmission line parameters also contribute to the total radiated power of the lines. The attempt to quantize radiation locally, fails because radiation describes a long-range (integral) interaction. However, it can be stated that at stronger inhomogeneities the local contributions to radiation increase.

Apertures in shielding enclosures are an important issue for determining shielding efficiencies. Bethe’s theory describes the coupling via field excited dipole moments at the location of the aperture. This approach neglects the reaction of the dipoles on the exciting field and therefore violates energy conservation. This work emphasizes an analytical asymptotic approach for coupling between half-spaces through small apertures, which allows an understandable generalization of Bethe’s theory.