GB1473957A - Waveguides - Google Patents

Abstract

1473957 Waveguides for circular-electric mode FELTEN & GUILLEAUME KABELWERKE AG 23 May 1975 [28 June 1974] 22929/75 Heading H1W [Also in Division C7] A waveguide suitable for transmission of the TE 01 circular-electric mode comprises an external tube of high-strength material, an inner layer of conductive material and a coating of dielectric material on the latter formed by a hard-anodizing process. The external tube may be made of steel, the conductive material may be copper, aluminium or silver and the dielectric may be aluminium or magnesium oxide. Where copper is used, a coating of aluminium is applied and converted wholly or partially to aluminium oxide by a known hard-anodizing process. The thickness of the oxide may be from 20 to 150 Á, preferably 60 to 80 Á. Alternatively, the copper layer may be omitted and the conductive material may consist of aluminium in a layer of thickness between 100 and 300 Á. The steel tube is preferably made by bending and seam-welding. The internal layer or layers of conductive material may be applied after formation of the tube, e.g. by electroplating or they may be applied before this step, e.g. by electrolytic or chemical plating, spraying, rolling or vapour-deposition.