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:
Dec. 04, 2001
Filed:
Feb. 18, 2000
Kuniyoshi Yokoo, Sendai, JP;
Hidenori Mimura, Sendai, JP;
Tohoku University, Sendai, JP;
Abstract
In a field emission cathode emitting an electron beam modulated by any desired high frequency, a cathode tip is formed in one surface of an N type semiconductor substrate constituting a collector region, an insulating layer formed on the one surface of the semiconductor substrate to have an opening which surrounds said cathode tip, a gate electrode is formed on the insulating layer to have an opening which surrounds the cathode tip, a P type base region is formed in the other surface of the semiconductor substrate, a base electrode is formed on the base region, an N type emitter region is formed in the base region, and an emitter electrode is formed on the emitter region. A DC supply source is connected across the gate electrode and the emitter electrode and a high frequency supply source is connected across the base electrode and the emitter electrode. Then, an electron beam modulated by a high frequency within the millimeter wave or microwave region of the high frequency supply source can be emitted efficiently from said cathode tip. Additionally, an electron beam modulated at a high frequency is generated by applying the Gunn effect in a compound semiconductor to a field emission cathode. The thus generated electron beam is cooperated with a cavity resonator or Fabry-Pérot resonator, and an electromagnetic wave within the millimeter wave or microwave region can be efficiently generated.