A Study of Single-Surface Corrugated Guides

A series of experiments were conducted to determine the properties of single-surface corrugated structures as transmission lines and as radiators. Two types of surfaces were tested: the first is a flat grooved plate fed by a waveguide; the second, a circular, corrugated cylinder fed by a coaxial line. A modification of the second type results in a spirally grooved rod with similar properties. The measured field parameters are found to be predictable from existing theory. For properly designed structures the energy is essentially bound to the corrugated surface; little radiation occurs, and the attenuation of the traveling wave is due chiefly to losses in the metal. The effect of filling the corrugations with solid dielectric is also analyzed.