| 摘要 |
PURPOSE:To reduce noise components, in improving the cathode structure of a magnetron, by providing a cylindrical base body adjacent to cathodes so as to constitute a third electrode, and supporting mechanically the third electrode in the neighborhood of a cathode stem, sufficiently apart from the cathodes, with an insulating member provided between the third electrode and the member supporting the third electrode. CONSTITUTION:A third electrode 60 is supported with a cathode supporter located sufficiently apart from the location of cathodes 25, with an insulator provided between the electrode 60 and the cathode supporter, and the ends of the electrode 60 are left unsupported. When the electrode 60 is made to have an electric potential negative to the cathode 25 by about -100--500V, plus ions, which concentrate on the trough of electric potential, are immediately captured by the electrode 60. Thus, plus ions flow into the electrode 60 without staying around the cathodes 25, and an unstable neutralization phenomenon between electrons and ions is not caused around the cathodes 25. As a result, generation of noises of below 1,000MHz order, especially is securely suppressed. |
