The feedforward gain amendment means which output the first amendment gain coefficient which takes

摘要

PROBLEM TO BE SOLVED: To provide an automatic gain control circuit capable of adjusting the level of a burst signal at a desired level with high accuracy at a high speed, even in a low C/N environment in a burst receiving modem.;SOLUTION: The automatic gain control circuit has a feedforward gain correction means for inputting a receiving signal and outputting a first correction-gain coefficient taking a predetermined value in response to a receiving-signal level, and a first gain variable means for inputting the receiving signal and correcting and outputting the receiving-signal level by a second correction-gain coefficient from a post stage. The automatic gain control circuit further has a feedback gain correction means for inputting an output from the first gain variable means and outputting the second correction-gain coefficient controlled so that the output level of the output is kept constant, and a selecting means for selecting and outputting either of the first correction-gain coefficient and the second correction-gain coefficient. The automatic gain control circuit further has a second gain variable means for inputting the receiving signal and correcting and outputting the receiving-signal level by the correction-gain coefficient selected by the selecting means.;COPYRIGHT: (C)2007,JPO&INPIT