ヤマジ タカフミ   Yamaji Takafumi
  山路 隆文
   所属   崇城大学  情報学部 情報学科
   崇城大学大学院  工学研究科 応用情報学専攻(博士後期課程)
   崇城大学大学院  工学研究科 応用情報学専攻(博士前期課程)
   職種   教授
取得国 国外
特許番号 USP 5,867,777
取得年月日 1999/02/02
発明者 Yamaji; Takafumi (Ichikawa, JP), Itakura; Tetsuro (Tokyo, JP), Tsurumi; Hiroshi (Kawasaki, JP)
特許名 Variable-gain amplifier circuit, offset control method in variable-gain amplifier circuit, radio receiver with variable-gain amplifier circuit, and radio receiving method in radio receiver with variable-gain amplifier
特許概要 A variable-gain amplifier circuit has an offset correcting function by which the fluctuation of offset due to the switching of a gain is decreased. In an offset detection mode, an input offset voltage of the variable-gain amplifier circuit is inputted to an offset retaining section, and in a signal amplifying mode, the offset is corrected by subtracting the output of the offset retaining section from an input signal by means of an input section of the variable-gain amplifier circuit. In addition, the variable-gain amplifier circuit can be applied to a radio receiver. The offset produced in a baseband section of a receiver is corrected by the offset correcting function of the variable-gain amplifier circuit, so as to prevent the quality of communication from being deteriorated.