Coated Lines with Local and Non-local Excitation

Dielectric conductors, fiber optics, microstrip technique and dielectric covered conducting lines play an important role in the present development of tele-communications. We are interested in studying and developing analytic methods to evaluate the surface waves and the space waves of dielectricly covered conducting lines. Capacitive excitation as well as excitation by means of a TEM-wave are considered. At first we treated the general case of a coated line with an elliptic cross section. We derived, based on a field representation by Bromwich potentials, an integral equation for the electromagnetic field. In the special cases of plane or circular cylindrical conductors with capacitive excitation, these equations were solved by applying the Fourier transformation or the Wiener-Hopf factorization, if the field is excited by a TEM mode. The obtained results can be used to determine the efficiency of excitation.