BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view illustrating the structure of a general microwave tube;
FIG. 2A is a longitudinal sectional view illustrating a collector in a conventional microwave tube;
FIG. 2B is a cross-sectional view taken along line A-A′ in FIG. 2A;
FIG. 3A is a longitudinal sectional view illustrating the structure of a collector in a microwave tube according to one embodiment of the present invention; and
FIG. 3B is a cross-sectional view taken along line A-A′ in FIG. 3A.