Magnetron

Patent metadata

Field	Value
Publication number	US-9653246-B2
Application number	US-201514950818-A
Country	US
Kind code	B2
Filing date	Nov 24, 2015
Priority date	Dec 3, 2014
Publication date	May 16, 2017
Grant date	May 16, 2017

Abstract

To provide a magnetron improved in high efficiency and load stability while suppressing costs. By shortening the height of vane Vh so that the ratio of the height of vane Vh to a gap between end hats EHg (EHg/Vh) satisfies a condition 1.12≦EHg/Vh≦1.26, an input side pole piece-vane gap IPpvg becomes larger than an output side pole piece-vane gap OPpvg, and an input side end hat-vane gap IPevg becomes larger than an output side end hat-vane gap OPevg, load stability at high efficiency can be improved while shortening the height of vane Vh. Therefore, it is possible to provide a magnetron improved in high efficiency and load stability while suppressing costs.

First claim

What is claimed is:

1. A magnetron comprising:
an anode cylinder extending cylindrically along a central axis of the magnetron extending from an input side to an output side;
a plurality of vanes extending from an inner surface of the anode cylinder toward the central axis with free ends forming a vane inscribed circle;
a cathode disposed along the central axis in the vane inscribed circle formed by the free ends of the plurality of vanes;
an input side end hat and an output side end hat respectively fixed to an input side end and an output side end of the cathode;
an input side pole piece and an output side pole piece respectively disposed at an input side end and an output side end of the anode cylinder in the central axis direction to lead magnetic flux into an electron interaction space between the free ends of the plurality of vanes and the cathode; and
magnets respectively disposed outside of the input side pole piece and the output side pole piece in the central axis direction;
wherein when a gap between the input side end hat and output side end hat is represented by gap between end hats EHg, a length of the vanes in the central axis direction is represented by height of vane Vh, a gap between the input side end hat and an input side end of the vanes is represented by input side end hat-vane gap IPevg, a gap between the output side end hat and an output side end of the vanes is represented by output side end hat-vane gap OPevg, a gap between a central part of a flat surface of the input side pole piece and the input side end of the vanes is represented by input side pole piece-vane gap IPpvg, a gap between a central part of a flat surface of the output side pole piece and the output side end of the vanes is represented by output side pole piece-vane gap OPpvg, and when a gap between a central part of a flat surface of the input side pole piece and the central part of the flat surface of the output side pole piece is represented by PPg,
conditional expressions 7.0 (mm)≦Vh≦8.0 (mm), 1.12≦EHg/Vh≦1.26, IPpvg>OPpvg, IPevg>OPevg, and 1.35≦PPg/Vh≦1.45 are satisfied.

2. The magnetron according to claim 1 , wherein
a conditional expression 0.9 (mm)≦(OPevg+IPevg)≦1.8 (mm) is satisfied.

3. The magnetron according to claim 1 , wherein
the input side end hat protrudes to a vane side more than the central part of the flat surface of the input side pole piece.

4. The magnetron according to claim 3 , wherein
when a diameter of the central part of the flat surface of the input side pole piece is represented by flat diameter of input side pole piece IPppd, and a diameter of the central part of the flat surface of the output side pole piece is represented by flat diameter of output side pole piece OPppd,
a conditional expression 1≦IPppd/OPppd≦1.34 is satisfied.

5. The magnetron according to claim 4 , wherein
when a radius of the vane inscribed circle is represented by radius of vane inscribed circle ra, and a radius of an outer periphery of the cathode is represented by radius of cathode rc,
a conditional expression 0.45≦rc/ra≦0.487 is satisfied.

Assignees

• Toshiba Hokuto Electronics Corp

Inventors

• Kato Naoya

Classifications

• H01J23/05

  having a cylindrical emissive surface, e.g. cathodes for magnetrons · CPC title

• H01J25/587

  Multi-cavity magnetrons · CPC title

• H01J25/50 Primary

  Magnetrons, i.e. tubes with a magnet system producing an H-field crossing the E-field (with travelling wave not moving completely around the electron space H01J25/42; functioning with plural reflection or with reversed cyclotron action H01J25/62, H01J25/64) · CPC title

• H01J23/04

  Cathodes · CPC title

• H01J23/10

  Magnet systems for directing or deflecting the discharge along a desired path, e.g. a spiral path (magnetic focusing arrangements H01J23/08) · CPC title