Patent ID: 6326729
Filing Date: 2001-12-04
Classification: H01J

Abstract:
A field emission cathode comprising:a collector region made of an N type semiconductor material;at least one cathode tip formed in a surface of said collector region;an insulating layer provided on the surface of said collector region and including at least one opening which surrounds said at least one cathode tip;a gate electrode provided on said insulating layer and including at least one opening which surrounds said at least one cathode tip;a base region made of a P type semiconductor material and being provided such that a pn junction is formed between said collector region and said base region; andat least one emitter region made of an N type semiconductor material and being provided such that a pn junction is formed between said base region and said at least one emitter region;wherein by connecting a high frequency supply source across the emitter region and the base region and by connecting a DC supply source across the gate electrode and the emitter region, an electron beam modulated in accordance with a high frequency of said high frequency supply source is emitted from said cathode tip.