Hyper-Frequency Wave Guides---General Considerations and Experimental Results

HIS paper describes a novel form of electrical propagation by means of which extremely high-frequency waves may be transmitted from one point to another, through specially constructed wave guides. The guide used for this purpose may take any one of several different forms. It may be a hollow copper pipe, which for the higher frequencies now available would be about 3 or 4 inches in diameter, or possibly a somewhat smaller conducting tube filled with some insulating material combining high dielectric constant and low loss, or it may conceivably be a rod or wire of dielectric material. 1 The phenomena involved in this form of transmission are exceedingly interesting and at first sight paradoxical for in some cases transmission is effected through a single wire of insulating material surrounded by metal in place of a pair of metal wires surrounded by insulation. In others the wire is made entirely of insulating material. In still others electrical effects are observed only on the interior of hollow metal cavities instead of the exterior only as is ordinarily experienced. In all cases there is no return current path, at least of the kind that is commonly assumed in ordinary transmission. The frequencies appropriate for this form of transmission begin at the higher of those generally known as ultra-high frequencies that is, 2000 mc. (X = IS cm.) and extend to an indefinite upper limit possibly *To be presented at joint meeting of Amer. Phys. Soc. and I.R.E., Washington D. C., April 30, 1936.