Modulator switch with low voltage control
US4596945A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 14, 1984 |
| Grant date | Jun 24, 1986 |
| Priority date | — |
| Expiry date | May 14, 2004 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01J17/14
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A cold-cathode, plasma discharge modulator switch is disclosed. A crossed-field discharge plasma supplied charge carriers for the switch. A dc magnetic field is employed to provide a highly localized cusp magnetic field near the cathode, so that gas ionization occurs primarily in the cathode-source grid gap. The region between the cathode and anode is filled with a relatively low pressure gas. A highly transparent control grid with small apertures is closely spaced from the anode. The switch is closed through application of positive potential (relative to the plasma) to the control grid, and opened through application of negative potential relative to the plasma to the control grid. The application of negative potential to the control grid creates an ion sheath around the control grid which permits plasma cut-off to the anode region provided the sheath size is larger than the control grid aperture radius. Upon plasma cut-off, the switch current is interrupted as the remaining plasma in the control grid-anode gap decays. Low pressure operation insures that ionization cannot sustain the plasma in the narrow, isolated control grid-anode gap.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.