CATHODE STRUCTURE OF MAGNETRON USED FOR MICROWAVE OVEN

摘要

PURPOSE: A cathode structure of a magnetron used for a microwave oven is provided to emit electrons through a combined method of direct heating and indirect heating, thereby improving characteristics and reliability of the magnetron based on low-temperature driving and long life of the cathode. CONSTITUTION: A cathode of a magnetron has top and bottom end shields(103,104) through which power is provided, and a spiral heater wire(101) which is placed between the top and bottom end shields and heated when the power is provided. The cathode generates electron energy by heating the heater wire. An electron emitting structure(102) comes into contact with a portion of the heater wire. The electron emitting structure is formed in a manner that electron emitting material is impregnated into a porous tungsten sponge. The electron emitting material is absorbed into the other portions of the heater wire to be coated on the portions.