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

A peculiar form of electrical propagation is described below. It makes use of extremely high frequencies — even beyond those generally employed in radio. In some respects it resembles ordinary wire transmission but unlike the latter there are no return conductors, at least of the usual kind. In this transmission, electromagnetic waves are sent through guides made up either of an insulator alone or of an insulator surrounded by a conductor. In a special case this insulator may be air. There are at least four different types of waves or electrical configurations that may be propagated. One of them is such that theory indicates its attenuation through a hollow conductor continuously decreases with increase of frequency. Although the paper deals largely with the nature of this transmission, some of the fundamental pieces of apparatus used in experimental work are described. They include generators, receivers and wave-meters.