Patent ID: 6417622
Filing Date: 2002-07-09
Classification: H01J

Abstract:
An integral polepiece focusing structure for an RF amplification tube, comprising:an interaction structure comprising a plurality of magnetic polepieces and a plurality of electrically conductive non-magnetic plates which are alternatingly and integrally coupled into a laminate structure; means for inducing a magnetic field in said interaction structure having lines of flux which flow through said magnetic polepieces; an electron beam tunnel extending through said interaction structure, said magnetic polepieces extending substantially entirely to said electron beam tunnel; and wherein said non-magnetic plates each have a respective cavity, each said respective cavity providing a respective resonant cavity, said magnetic polepieces each having at least one respective iris, wherein said at least one iris couples an applied electromagnetic signal between adjacent ones of said resonant cavities, said at least one iris having a center portion with a first width and flared ends each having a second width that is greater than said first width, said flared ends wrapping partially around said electron beam tunnel, said flared ends each further having a side defining an edge of said iris adjacent to said electron beam tunnel that extends to said center portion in a direction substantially intersecting said sidewall such that a portion of a corresponding one of said magnetic polepieces remains between said edge and said electron beam tunnel; wherein said at least one iris further comprises: a first iris located on a first side of a first one of said magnetic polepieces and a second iris located on a second side of said first one of said magnetic polepieces; a third iris located on a first side of a second one of said magnetic polepieces and a fourth iris located on a second side of said second one of said magnetic polepieces; and wherein said third iris is aligned with said first iris and said fourth iris is aligned with said second iris.