| 摘要 |
PROBLEM TO BE SOLVED: To provide an AGC circuit which can reduce a distortion due to an amplifier from a starting time of a gain attenuation. SOLUTION: An AGC circuit is provided with a variable attenuator 21 and a variable gain amplifier 26 at a subsequent stage, wherein an attenuation amount of the variable attenuator 21 and a gain of the variable gain amplifier 26 are controlled by a common AGC voltage, the attenuation amount of the variable attenuator 21 is made large by controlling only the attenuation of the variable attenuator 21 in a range from a start of a gain attenuation by the AGC voltage to a predetermined voltage, and a signal level inputted to the variable gain amplifier is lowered in a predetermined range from the gain attenuation start by the AGC voltage by controlling the attenuation of the variable attenuator 21 and the gain of the variable gain amplifier 26. COPYRIGHT: (C)2006,JPO&NCIPI
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