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:
Oct. 02, 2001
Filed:
Aug. 04, 2000
Yehuda Goren, Palo Alto, CA (US);
Sungho Jin, Millington, NJ (US);
Gregory P Kochanski, Dunellen, NJ (US);
Wei Zhu, Warren, NJ (US);
Other;
Abstract
An improved gridded microwave tube is provided, the tube containing a cold cathode, an anode, and a grid located between the anode and cathode. In one embodiment, the cold cathode has a refractory metal substrate and carbon nanotube emitters, the emitters having a diameter of 1 to 300 nm and a length of 0.05 to 100 &mgr;m. The grid-cathode spacing is 1 to 100 &mgr;m, the grid contains apertures having a maximum dimension of 0.5 to 100 &mgr;m, and the grid thickness is 0.5 to 100 &mgr;m. Emission from the cathode directly onto the grid material itself, which undesirably heats the grid, is reduced by either (a) the presence of a shadow mask between the grid and the emitters or (b) selective formation of the emitters in locations that correspond to the grid apertures. The microwave tube operates at a frequency of greater than 0.5 GHz, advantageously greater than 2 GHz.