Vacuum tube including grid-cathode assembly with resonant slow-wave structure
US5317233A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 13, 1990 |
| Grant date | May 31, 1994 |
| Priority date | — |
| Expiry date | Apr 13, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J25/04
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A vacuum tube for amplifying an r.f. signal includes an assembly containing a cathode and grid for current modulating an electron beam derived from the cathode. One of the electrodes of the assembly includes a slow wave structure approximately resonant to the frequency of the signal. A cavity resonant to the frequency of the signal, positioned between the grid and a collector for the beam, is coupled to the beam. In one embodiment, the slow-wave structure is mounted in a support for the grid, while in a second embodiment, the grid is configured as plural, parallel meander lines forming the slow-wave structure. In the latter embodiment, the beam is preferably annular and the meander line geometry, in certain modifications, is adjusted so that there is a relatively small electric-field variation with radius over the portion of the grid through which the annular beam passes. In a further embodiment, the grid is configured as two interlaced spirals, driven by complementary replicas of the r.f. signal so the beam is formed at twice the frequency of the r.f. signal. Focusing electrodes configured as a perforated sheet, contacting the cathode, or as electrodes just downstream of the contr…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.