Yamaji Takafumi    Department   SOJO UNIVERSITY  Department of Computer and Information Sciences, FACULTY OF COMPUTER AND INFORMATIONSCIENCES      /(DC)Division of Applied Information Sciences, Graduate School of Engineering      /Division of Applied Information Sciences, Graduate School of Engineering    Position
Country of acquisition	Foreign country (米国)
Patent No.	USP 7,031,684
Date of Grant	2006/04/18
Inventor	Otaka; Shoji (Yokohama, JP), Yamaji; Takafumi (Yokohama, JP)
Patent Title	Variable gain amplifier device
Details	A variable gain amplifier device controlled by a first gain control signal comprises a gain controlled amplifier having a gain and including a differential pair of first and second MOS type transistors configured to operate in a weak inversion region; and a control signal converter configured to convert the first gain control signal into a second gain control signal, and supply the second gain control signal to the gain controlled amplifier to exponentially vary the gain with respect to the first gain control signal.