The use of ridge waveguide for scanners

Summary form only given, as follows. The use of ridge waveguide with a movable ridge has been proposed for a variable-phase scanner. There are mechanical and electrical problems with this system similar to those encountered in variable width waveguide scanners. Its scan is more restricted, but it does permit the use of longitudinal slots in the broadside of the guide. Expressions for the fields in the ridge waveguide are obtained by Hahn's method. Expressions are obtained also for the normalized shunt conductance of a narrow longitudinal slot of resonant length in the broad face of the guide opposite the ridge and for the characteristic impedance of the ridge waveguide. [NB: A manuscript annotationon the copy at hand states "see also Howery, R.W. 'An Improved Eagle Scanner - Proc. of Third Symposium on Scanning Antenns' - Nov 1950 (NRL ASTIA #134257 (C-6317) [Confidential] Bendix Dept 465 File #2241."]