Slow wave structure having oppositely curved conductors disposed about the beam and mounted transversely between opposite walls

Claim 1

IN A TRAVELLING WAVE TUBE HAVING A CYLINDRICAL ELECTRON BEAM AND A SLOW WAVE STRUCTURE SECURED TO METAL SIDE WALLS, THE BEAM-INTERACTING PORTIONS THEREOF COMFORMING CLOSELY TO THE PROFILE OF THE BEAM AND PROVIDING A TUNNEL THEREFOR, THE SAID BEAM-INTERACTING PORTIONS OF THE SLOW WAVE STRUCTURE INCLUDE A PAIR OF SIMILARLY SLOTTED BUT OPPOSITELY CURVED METAL SHEETS HAVING FLAT LONGITUDINALLY EXTENDING MARGINAL PORTIONS ON EACH SIDE FIXED TO SAID SIDE WALLS AND WHEREIN EACH SHEET IS SLOTTED TO FORM WITH THE SIDE WALLS A STUB-SUPPORTED MEANDER LINE PROVIDING A ZIGZAG CONDUCTING PATH FROM END TO END OF THE SLOW WAVE STRUCTURE, EACH SHEET HAVING A FIRST SET TRANSVERSE SLOTS EXTENDING ALTERNATELY FROM EACH SAID WALL AND TERMINATING WITHIN THE FLAT PORTION ADJACENT SAID SIDE WALL SPACED FROM THE CURVED PORTION AND A SECOND SET OF TRANSVERSE SLOTS ALONG THE LENGTH OF SAID STRUCTURE EXTENDING ALTERNATELY WITH SAID FIRST SET FROM EACH SIDE WALL AND FLAT PORTION OVER THE CURVED PORTION OF THE SHEET BEYOND THE AXIS OF THE TUNNEL AND TERMINATING AT A POSITION SPACED FROM THE JUNCTION OF THE CURVED PORTION OF THE SHEET WITH THE OPPOSITE FLAT MARGINAL PORTION, SAID SECOND SET OF SLOTS