Experimental studies on a beam waveguide for millimeter waves

The beam waveguide utilizes reiterative wave beams which are guided by resetting the cross-sectional phase distributions at periodic intervals. The major purpose of the measurements was to obtain data concerning the inherent losses of the guide, including the diffraction loss, caused by energy by-passing the phase transformers, and the dielectric and reflection losses of the transformers. Resonance measurements with an "open cavity," consisting of a section of a beam waveguide terminated by plane reflector walls, yielded the over-all losses of the phase transformers. In order to isolate the diffraction loss, pulse measurements were made between two reflectors, slightly curved to reset the phase distribution in the reflected beam. These measurements also gave information on the build-up of the reiterative wave beam. The experimental data support the theory which predicts that the diffraction losses of reiterative beams can be made extremely small.