Cathode structure for magnetrons
AssigneeHitachi, Ltd.
InventorTomokatsu Oguro
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Abstract
The cathode filament of a magnetron is constituted by a metallic cylindrical body provided with a plurality of perforations. The cylindrical body may be made of a cylinder or formed by helically winding a web of a metal strip.
Claims15
In a magnetron of the type including a cathode structure and an anode structure surrounding the cathode structure, wherein said cathode structure includes a filament, upper and lower end shields secured to the opposite ends of the filament for supporting the same, and a center support and a side support respectively supporting said upper and lower end shields and also acting as electric leads, the improvement comprising:
- a filament in the form of a metallic cylindrical body provided with a plurality of openings therethrough;
- said upper and lower end shields further including upper and lower cylindrical cups having the openings thereof facing each other for receiving the cylindrical filament
- and wherein the opposite ends of the cylindrical filament are contained within and supported by the cylindrical cups.
In a magnetron of the type including a cathode structure and an anode structure surrounding the cathode structure, wherein said cathode structure includes a filament, upper and lower end shields secured to the opposite ends of the filament for supporting the same, and a center support and a side support respectively supporting said upper and lower end shields and also acting as electric leads, the improvement comprising:
- a filament in the form of a metallic ribbon helically wound to form a cylindrical body with the ends of said ribbon connected to said end shields to define a helical current path therebetween, said web being perforated with a pattern of openings to reduce the cross-section of the ribbon as a current conductor while maintaining its overall area outline as an electron emitter.
The magnetron according to claim 13 or 14 wherein said perforations are arranged in such a pattern to control the direction of flow of the current flowing through said cylindrical body.
Dependencies are inferred from the claim text.