Simulation and theory of TEM transmission lines radiation losses

There are three kind of losses in transmission lines: ohmic, dielectric and radiation losses. While the first two are local phenomena which are easy to model, the radiation losses lack a simple model. We show that the losses model for the ohmic and dielectric allows a simple calculation of losses only in the case of matched line, and the calculation complicates in the case of unmatched line. The aim of this work is to find some possible radiation model for matched transmission lines.