Technology is described for vacuum electron device (e.g., sheet beam klystron) that includes a hollow tube structure. In one example, the hollow tube structure includes at least three resonant cavities and at least two drift tube sections. Each resonant cavity includes a cavity width along a major axis and a cavity height along a minor axis. Each drift tube section includes a drift tube section width and a drift tube section height, and the cavity height is greater than the drift tube section height. A first drift tube section is disposed between a first resonant cavity and a second resonant cavity. A second drift tube section is disposed between the second resonant cavity and a third resonant cavity. A drift tube section width of the first drift tube section is substantially different from a drift tube section width of the second drift tube section.

A magnetron for a microwave oven is provided that decreases noise in an ISM band by minimizing a size of a lower end shield, and thus, minimizing EMI generation. In the magnetron for the microwave oven, as a midpoint of a side lead hole is positioned inside a virtual circle formed by points positioned at a predetermined distance from a midpoint of the shield disc and a side lead is connected in a straight line, there are advantages that a further bending process is not generated and a defective rate that occurs in the manufacturing process of the shield disc may be decreased.

A magnetron for a microwave oven is provided that decreases noise in an ISM band by minimizing a size of a lower end shield, and thus, minimizing EMI generation. In the magnetron for the microwave oven, as a midpoint of a side lead hole is positioned inside a virtual circle formed by points positioned at a predetermined distance from a midpoint of the shield disc and a side lead is connected in a straight line, there are advantages that a further bending process is not generated and a defective rate that occurs in the manufacturing process of the shield disc may be decreased.

A magnetron for a microwave oven is provided that decreases noise in an ISM band by minimizing a size of a lower end shield, and thus, minimizing EMI generation. In the magnetron for the microwave oven, as a midpoint of a side lead hole is positioned inside a virtual circle formed by points positioned at a predetermined distance from a midpoint of the shield disc and a side lead is connected in a straight line, there are advantages that a further bending process is not generated and a defective rate that occurs in the manufacturing process of the shield disc may be decreased.

A magnetron for a microwave oven is provided that decreases noise in an ISM band by minimizing a size of a lower end shield, and thus, minimizing EMI generation. In the magnetron for the microwave oven, as a midpoint of a side lead hole is positioned inside a virtual circle formed by points positioned at a predetermined distance from a midpoint of the shield disc and a side lead is connected in a straight line, there are advantages that a further bending process is not generated and a defective rate that occurs in the manufacturing process of the shield disc may be decreased.

A large electron tube includes: a tubular collector; and a magnetic body disposed outside the collector and having no axial symmetry with respect to a center axis of the collector. This makes it possible to inhibit parasitic oscillation that occurs inside the collector.

A large electron tube includes: a tubular collector; and a magnetic body disposed outside the collector and having no axial symmetry with respect to a center axis of the collector. This makes it possible to inhibit parasitic oscillation that occurs inside the collector.

A magnetron includes a yoke, an anode unit including an anode cylinder, radially arranged vanes, and first and second pole pieces at both sides of the anode cylinder, a cathode unit having a filament spaced apart from the vanes, and an output unit having an antenna lead connected to one vane to radiate high-frequency microwaves. The first pole piece includes a first flat portion, a slope at an inner side of the first flat portion, a second flat portion at an inner side of the slope and having a diameter of 9.510.5 mm, a first hole formed in the second flat portion and having a diameter of 88.2 mm, and a second hole formed in the slope for penetration of the antenna lead. The magnetron achieves higher and stabilized efficiency, restricted oscillation efficiency variation, lower energy consumption, and improved load stability without deterioration of oscillation efficiency.

A magnetron includes a yoke, an anode unit including an anode cylinder, radially arranged vanes, and first and second pole pieces at both sides of the anode cylinder, a cathode unit having a filament spaced apart from the vanes, and an output unit having an antenna lead connected to one vane to radiate high-frequency microwaves. The first pole piece includes a first flat portion, a slope at an inner side of the first flat portion, a second flat portion at an inner side of the slope and having a diameter of 9.510.5 mm, a first hole formed in the second flat portion and having a diameter of 88.2 mm, and a second hole formed in the slope for penetration of the antenna lead. The magnetron achieves higher and stabilized efficiency, restricted oscillation efficiency variation, lower energy consumption, and improved load stability without deterioration of oscillation efficiency.