The Physical Reality of Space and Surface Waves in the Radiation Field of Radio Antennas* By

Evidence is presented which indicates that, notwithstanding the change in sign made by Sommerfeld in his 1926 paper on radio wave propagation, the radiation field of a vertical electric dipole may be separated into space and surface wave components. Sommerfeld's original concepts as to the characteristics of two such waves in radio transmission are largely substantiated. It is shown that a space and a surface wave are generated by a simple vertical dipole antenna at the surface of the earth and that this surface wave has the same wave tilt as the Sommerfeld surface wave. Evidence is given which would indicate that this surface wave travels around the curve of the earth in much the same manner as a guided wire wave travels around a bend on a wire. In the appendix formulas are given for the space and surface waves in the radiation fields of a horizontal electric dipole and of horizontal and vertical magnetic dipoles.