PROPAGATION OF MICROWAVES ON A SINGLE WIRE Part III

Abstract

Theoretical calculations for the radial field spread around a bare copper wire supporting the Sommerfeld wave, as a function of the percentage of power flow p and, also as a function of the wavelength of excitation, for 50%. 75% and 90% power flow have been made. The attenuation constant of the Sommerfeld surface wave line as a function of wire radius a for different values of wavelength has been calculated. Calculations have also been made for the radius of different constant power contours round a Harms~Goubau dielectric- coated surface wave line,as a function of the dielectric constant, dielectric coating thickness and radius of the supporting wire. An expression for the ratio of radii of constant power contour, with and without dielectric coating, for different percentages of power flow asa function of dielectric coating thickness has been derived. The variation of thisratio, at 3.45 ems wavelengths for a dielectric constant of 2.0, shows that the shrinkage of the radial field occurs rapidly up to a coating thickness of O.O1em. and then slowly up to 0.03 em. But beyond a cotaing thickness of 0.03 em, the shrinkage of the field is not appreciable.