| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem that a system for detecting DC offset voltage in a no-signal state and correcting a signal in accordance with the detection result is not suited to a system such as W-CDMA for continuously performing receiving operation. SOLUTION: In the gain control amplifier constituted by cascade connecting three GCA stages 11-13 e.g. , the center values of output DCs from respective GCA stages 11-13 are held at a fixed value by common feedback circuits 16-18 connected correspondingly to respective GCA stages 11-13 and DC feedback quantity is changed by a DC feedback circuit 19 connected between the output side of the final stage of the GCA stages 11-13 and the input side of the initial stage in accordance with gain control voltage VG. COPYRIGHT: (C)2004,JPO
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