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:
Nov. 29, 2011
Filed:
Jun. 09, 2010
Takehito Kamimura, Tokyo, JP;
Norio Chujo, Tokyo, JP;
Takehito Kamimura, Tokyo, JP;
Norio Chujo, Tokyo, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
There is provided a variable gain circuit system which is inductorless and capable of achieving a high gain and a wide band by elements for achieving variable gain to prevent decreasing a gain or deteriorating the band. The variable gain circuit includes: transistors; a resistor connected as a load of each transistor; a voltage source applying a bias voltage to each gate of the transistors; a switch selectively connecting the voltage source or a ground potential to each gate of the transistors in accordance with gain setting; and a current source connected to a common input. A drain of each transistor is connected to an input of a circuit in a subsequent stage.