Cathode structure for magnetron

Abstract

A cathode structure for a magnetron representative of a self-oscillation type microwave electron tube comprises a pair of opposite end shields for supporting both ends of a filament helically wound in an axial direction, and a getter fixed on at least an upper end shield positioned on the side of a terminal from which a microwave oscillation output is produced. The upper end shield is concaved with respect to a lower end shield, and the getter provided on the upper end shield is also concaved so as to be closely fitted over substantially the entirety of an outer surface of the upper end shield. Preferably, the getter provided on the upper end shield has an upright annular wall of a central burring hole. Thus, the improved cathode structure is immune to deformation and suitable for cleaning and welding, thereby ensuring improved lifetime stability and high fabrication efficiency.

Dependencies are inferred from the claim text.