Patent ID: 9653246
Date: 2017-05-16
CPC Classifications: H01J

Claim:
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.