Patent ID: 6404301
Filing Date: 2002-06-11
Classification: H01J

Abstract:
A method of forming a noise filter of a magnetron in which a filter including a cathode terminal of a magnetron, a through type capacitor and a choke coil is connected with the cathode terminal, the method comprising the steps of:obtaining a first resonant point at a high frequency bandwidth implemented by using a transmission line model; setting a length of a first portion of a copper line of the choke coil for enhancing an attenuating ratio of a resonant frequency with respect to the first resonant point; forming a tightly wound portion of the choke coil by tightly winding the first portion of the copper line having the thusly set length onto a ferrite; obtaining a second resonant point with respect to an oscillation frequency reflected from an interior of the magnetron; and setting the length of a second portion of the copper line for thereby obtaining the second resonant point and forming a loosely wound portion of the choke coil by loosely winding the second portion of the copper line having the thusly set length, spaced from the tightly wound portion.