Magnetron using combined cold cathode head and production method of cold cathode body

Abstract

The invention is a production method of a magnetron using a combined cold cathode head and a cold cathode body in the cold cathode head. The magnetron includes upper and lower tube shells, input and output ceramic cylinders, and an exhaust pipe head. The magnetron housing including the anode cylinder and the upper and lower magnetic poles, the blades set in the anode cylinder, the upper and lower shielding caps, the combined cold cathode head composed of electrode wire and cold cathode body, and the power supply connecting rod. The production method of the cathode component, the antenna and the cold cathode body includes: material preparation and ball milling, pressing and molding, and sintering. In this invention, the filament of the traditional hot cathode is used as the electrode wire and the secondary electron emitter. Under the high voltage of the cathode and anode, the cold cathode body forms a field emission to generate primary electrons. The power supply connecting rod is connected to the lower shielding cap during operation. The temperature of some parts is lower than 500°C. Therefore, it has the characteristics of large emission flow and stable emission, high efficiency, good electromagnetic compatibility, long life, high reliability, simple and reliable production process, and low cost.

Description

technical field [0001] The invention relates to the technical field of a magnetron for microwave generation, in particular to a method for producing a magnetron using a combined cold cathode head and a cold cathode body in the cold cathode head, using the combined cold cathode head emission system The magnetron is especially suitable as a microwave source for microwave application equipment including domestic microwave ovens. Background technique [0002] Magnetron is the most widely used electronic vacuum tube. Because of its small size, high power, and convenient use, it is used as a microwave source for microwave application equipment including household microwave ovens. The cathode emission system in the magnetron structure is the heart of the whole tube. The working characteristics of the cathode have a great influence on the performance and life of the tube, so improving the working characteristics of the cathode has become an important research content; the convention...

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Problems solved by technology

When this type of traditional magnetron works normally, it needs to provide a certain current to the filament. The cathode needs to be heated with a power of about 40W between the center support and the upper electrode power connecting rod and the side support and the upper electrode power connecting rod. When the temperature rises to 800-1000°C, electrons are emitted, and the electrons bombard the cathode under the action of a magnetic field and raise its temperature to about 1800°C; working at such a high temperature will bring a series of problems, such as When the traditional magnetron is working, especially when it is intermittently working, it is repeatedly subjected to the influence of uneven stress such as expansion at high temperature and contraction at cooling, which will deform the high-voltage ceramics that are sealed and connected to the power connecting rod, seriously affecting the connection between the power connecting rod and the power supply. The tightness between the high-voltage ceramics reduces the vacuum degree of the magnetron, which in turn affects the performance and life of the magnetron; The electrons inside the body use additional energy to make some electrons escape across the surface barrier of the emitter to generate secondary harmonics and electromagnetic noise, which seriously affects the performance of the magnetron.

[0004] In the article "Film Field Emission Cold Cathode" (see "Optoelectronics Technology" No. 04, 1989, author: Chen Lifang et al.), a micro-electron source using a three-sandwich structure cold cathode is reported, which has room temperature work and no cathode work. consumption, no warm-up delay, etc., but it uses a planar emission structure, which needs to add a gate, and the emission current is small, so it cannot provide secondary electron emission; while the application number is CN201510675065.0, and the invention name is "A Kind of The carbon nanotube cold cathode disclosed in the patent document "Microwave Modulation Cold Cathode Micro-array Radiation Source and Its Realization Method" also adopts a planar emission structure, which cannot provide secondary electron emission and is not suitable for application in magnetrons; "Development of Ku-band Cold Cathode Magnetron" (see: Chinese Institute of Electronics Vacuum Electronics Branch - Fourteenth Annual Meeting, 2004, TN123, author: Zhou Caiyu et al.) discloses a method using cold cathode magnetron Provide primary electron emission, and use the primary electrons to bombard the surface of the secondary emitter to generate secondary electrons, but because it uses an alloy cathode structure, the ability of the primary electrons provided by the micro-tip field emission on the surface of the alloy cathode is insufficient, and the large pulse The transmission output power is only about 50kW, which is only suitable for use in medium and small tubes of Ka-band, Ku-band and X-band

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