In current satellite communications, the working frequency is increasing more and more in order to obtain higher bandwidths and higher data transmission speeds. However, increasing the frequency implies that losses per unit length in the different transmission media are also increased. And with it, an increase in the whole system noise and the thermal dissipation becomes a problem. Thus, in recent years, the reduction of transmission losses, especially of the waveguides that connect the power amplifiers with the antennas, has become a hot topic, and therefore, the aforementioned decrease is an objective of undeniable interest, with strong impact at system level. The main objective of this thesis will be to design, manufacture and then validate transmission media in which losses are lower than those which are currently in use at Ka, Q, V and W bands. Telecommunication and earth observation systems will benefit from this development.