Multibeam klystron
View Patent ↗A multibeam, electrostatically focused klystron includes a plurality of conductive members, ones of which are recessed to provide input and output sections of microwave cavities, wherein focusing voltage is applied between those sections. The conductive members are either spaced along the path of multiple beams, or stacked in insulated relation, in either case being supported by glass rods within a glass envelope.
1. A klystron construction comprising:
an electron gun structure providing a plurality of electron beams, collector means receiving said electron beams, and means intermediate said gun structure and said collector means through which said electron beams pass,
said intermediate means comprising toroidal cavities receiving said electron beams proximate the toroidal axes thereof,
means providing an r.f. input to a first of said cavities and means receiving an r.f. output from another of said cavities farther along the path of said electron beams,
wherein ones of said cavities comprise an input section, and an output section electrically insulated from the input section, and
means for providing a voltage between said sections for electrostatically focusing said electron beams.
2. The klystron construction according to claim 1 further including:
an elongated envelope enclosing said electron gun structure, said collector means, and said intermediate means, said envelope being formed of insulating material, and
a plurality of insulating rods supported within said envelope and in turn supporting said electron gun structure, said collector means and said intermediate means.
3. The klystron construction according to claim 1 wherein at least said intermediate means comprise a plurality of adjacent conductive members centrally apertured to pass said electron beams, and including insulating material separating certain next adjacent ones of said adjacent conductive members, and
wherein said certain next adjacent ones of said members are centrally recessed to form said input and output sections of said cavities.
4. The klystron construction according to claim 3 wherein said conductive members comprise stacked metal disk members.
5. The klystron construction according to claim 4 wherein said insulating material comprises an insulating material with high dielectric constant and low RF loss.
6. The klystron construction according to claim 3 further including:
an elongated envelope enclosing said electron gun structure, said collector means, and said intermediate means, said envelope being formed of insulating material, and
a plurality of insulating rods disposed within said envelope, said conductive members being secured to said insulating rods.
7. The klystron construction according to claim 6 wherein ones of said conductive members are supported in spaced relation by said insulating rods.
8. The klystron construction according to claim 6 wherein said conductive members comprise a stack of metal disk members.
9. The klystron construction according to claim 1 including at least three such cavities, including at least one additional cavity between said first of said cavities and said another of said cavities along the path of said electron beams.
10. The klystron construction according to claim 4 wherein said insulating material comprises insulating sheet with high dielectric strength to prevent voltage breakdown and high dielectric constant to confine RF fields and low loss tangent to maintain cavity Q.
11. The klystron construction according to claim 10 wherein said insulating material comprises alumina.
12. The klystron construction according to claim 4 , wherein said insulating material comprises ceramic or mica.
13. The klystron construction according to claim 12 wherein said insulating material comprises alumina.