CATHODE-MESH ASSEMBLY WITH SPATIALLY-DEVELOPED AXIALLY SYMMETRIC FIELD-EMISSION CATHODE Russian patent published in 2019 - IPC H01J1/304 

FIELD: electrical engineering.

SUBSTANCE: invention relates to electronic engineering, in particular to cathode-mesh assemblies for vacuum electronic devices, including high-power microwave devices with microsecond readiness time. Cathode-grid assembly includes a plurality of cells consisting of a space-developed annular field-emission cathode with a large aspect ratio of dimensions, and a grid electrode with holes. Peripheral part of the mesh electrode in the cell, which limits the slot hole, has thickness H greater than the thickness of the central part of the mesh electrode h, which limits the slot hole from the inner side. Thickness of the peripheral part of the mesh electrode and the thickness of the central part of the mesh electrode are related by ratio 3h>H>1.5h. Top of the circular field-emission cathode is shifted in radial direction from the peripheral boundary of the slot to the axis of symmetry of the CMA at distance l>L/2.

EFFECT: reduced angle of divergence of trajectories of electrons at the outlet of the grid electrode due to reduced defocusing action of the electrostatic lens.

1 cl, 2 dwg