Abstract :
High-power microwave transmission is hampered primarily by the relatively high transmission loss of waveguides. Because of the skin effect, the current flow in any guiding structure is restricted to very thin surface layers. Assuming one and the same current distribution on a conductor, the loss increases with the square root of the frequency. Therefore, efficient power transmission by microwave requires the transmission of wave fields or modes which are associated with very low currents on the guiding structure.