The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 24, 1986
Filed:
May. 14, 1984
Robert W Schumacher, Canoga Park, CA (US);
Robin J Harvey, Thousand Oaks, CA (US);
Hughes Aircraft Company, Los Angeles, CA (US);
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.