The beam waveguide

As Goubau has already pointed out, the transfer of power between a source and collector by means of electromagnetic wave beams can be accomplished if there are beams whose (phase and amplitude) distribution in a transverse plane repeats itself at periodic intervals. That such beams exist had been theorized, and that they may be approximated in practice has been demonstrated in the last few years. The important work in this area was that of Goubau, who reported the invention of the beam mode waveguide in 1959.²³ Since 1960, this work has been independently confirmed and extended by many others, notably workers at the Bell Telephone Laboratories. Confirmation of the theoretical results in the millimeter range (23 Gc/s) by the construction of a beam-mode transmission line was reported in 1961 by Goubau and Christian,²¹ while Brown and Heenan² have transferred power utilizing these principles both in the millimeter range (36.5 Gc/s) in 1962 and in the S band (2400–3100 Mc/s) in 1963.