Magnetron tube with improved low cost structure

Claim 1

A magnetron for the generation of microwave oscillations comprising: a multicavity cylindrical anode structure; end closures at both ends of said anode structure and insulated therefrom consisting of re-entrant, closed-ended hollow sections defining a vacuum enclosure; an electron source consisting of a helical metallic filament coaxial with said cylindrical anode structure and connected at both ends by means of cylindrical metallic support members affixed to or integral with the inside flat surfaces of said re-entrant end closures; electrical conductors connected to each of said end closures for the purpose of heating said filament to electron emitting temperature by passing an electrical current therethrough and for rendering said end closures and said filament at high negative potential with respect to said anode structure; output means consisting of a coaxial transmission line connected between said anode structure and one or more anode resonators and having its center conductor terminated in an antenna with its axis perpendicular to the axis of said anode structure; mode suppression means connected to alternate sets of alternate resonators and consisting of metallic conductors; magnets adjacent to said end closures configured to produce a magnetic field in the interaction space between said anode and said filament in a direction parallel to the axis of said anode and said filament and at the same electrical potential as said filament; microwave leakage suppression means consisting of coaxial choke sections of predetermined length relative to the operating frequency of said magnetron supported by said anode structure and surrounding said re-entrant portions of both end closures in close proximity; a magnetic return path for guiding magnetic flux lines from the outer extremity of the first said magnet to the outer extremity of the second said magnet and insulated therefrom; cooling means in thermal contact with said cylindrical anode outer surface.