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:
Sep. 16, 1980
Filed:
Jan. 12, 1979
Applicant:
Inventor:
John M Osepchuk, Concord, MA (US);
Assignee:
Raytheon Company, Lexington, MA (US);
Primary Examiner:
Int. Cl.
CPC ...
H01J / ;
U.S. Cl.
CPC ...
315 3971 ; 313 38 ; 313 46 ; 315 3951 ; 315-535 ;
Abstract
A microwave tube having a heated cathode with a rare earth magnet positioned inside the evacuated envelope of the tube and at least partially shielded from thermal radiation from the cathode and/or anode so that the magnet may be operated at elevated temperatures while protected from environment such as oxygen in the air to prevent degradation of the magnetic properties of the magnet at temperatures up to 500.degree. C. during processing of the tube or up to 250.degree. C. during operation of the tube with thermal shielding from the hot cathode preventing any surface of the magnet from exceeding such temperatures.