Electron beam tubes including a vacuum envelope seal and having a metallized balance ring
US7187130B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 5, 2004 |
| Grant date | Mar 6, 2007 |
| Priority date | — |
| Expiry date | Mar 5, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J23/12
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A linear electron beam tube comprises an electron gun having a cathode and a grid, and an anode arranged in a first portion of a drift tube. The drift tube is within a vacuum envelope and has first and second portions separated by a gap at which point an electron beam, density modulated with an input RF signal is inductively coupled to an output cavity. The vacuum envelope is partially defined by a cylindrical ceramic wall and a pair of ferromagnetic pole pieces at its ends that form a DC magnetic circuit. The pole pieces extend radially beyond the vacuum envelope. At least those parts of the surface of the pole pieces that are in the RF path are coated with a layer of relatively low RF loss material such as copper. A balance ring separates the ceramic from the pole pieces. Further reduction in RF losses and relief from thermal stresses is obtained by forming the balance ring from the same ceramic as the cylindrical wall and metallizing at least that part of the outer surface of the balance ring that is on the RF path.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.