Magnetron having a lowered oscillation frequency and processing equipment employing the same

Processing equipment comprising:

• a magnetron comprising an anode cylinder, a plurality of vanes extending radially inwardly from said anode cylinder, a cathode filament extending along a center axis of said anode cylinder, an output section including an antenna coupled to one of said plurality of vanes, and a magnetic circuit section for supplying a magnetic field into said anode cylinder, said magnetron oscillating at a fundamental frequency in a range from 400 MHz to 600 MHz;
• and
• a processing section for processing a substance to be processed by using microwaves supplied from said magnetron,
• wherein said output section provides the microwaves to said processing section via a coaxial waveguide, and is provided with a cylindrical member surrounding a tip of said antenna, and an antenna block made of copper fixed to said cylindrical member is coupled to an inner conductor of said coaxial waveguide.

A magnetron comprising:

• an anode cylinder;
• a plurality of vanes extending radially inwardly from said anode cylinder;
• a cathode filament extending along a center axis of said anode cylinder;
• an output section including an antenna coupled to one of said plurality of vanes;
• and
• a magnetic circuit section for supplying a magnetic field into said anode cylinder,
• said magnetron oscillating at a fundamental frequency in a range from 400 MHz to 600 MHz,
• wherein a ratio F/G of an outside diameter F of said cathode filament to a diameter G of a circle tangent to tips of said plurality of vanes satisfies one of the following inequalities:
• 0.44≦F/G≦0.54, when N=8,
• 0.52≦F/G≦0.64, when N=10,
• 0.59≦F/G≦0.73, when N=12, and
• 0.63 F/G≦0.77, when N=14,
• where N is the number of said plurality of vanes.