Patent ID: 7081926
Filing Date: 2006-07-25
Classification: H03G,H04N

Abstract:
1. An automatic gain control apparatus for a video signal comprising: a RF amplifier for receiving signals of a frequency band from a predetermined channel, and amplifying a high frequency signal among those received signals and converting the high frequency signal into an intermediate frequency (IF) signal; an IF amplifier for receiving the intermediate frequency signal, and amplifying the signal by a predetermined amplifying rate; a demodulator for demodulating the IF signal from the IF amplifier, and outputting a reproduced video signal; a RF automatic gain control apparatus and an IF automatic gain control apparatus for receiving the video signal reproduced by the demodulator, and controlling a gain of the RF amplifier and a gain of the IF amplifier according to the reproduced video signal, respectively; and a RF automatic gain control compensating unit for detecting a level of an IF input signal provided to the IF amplifier, checking whether the detected level of the IF input signal meets a reference level, controlling for raising a voltage of the RF automatic gain control apparatus if the detected level of the IF input signal is lower than the reference level, and controlling for lowering a voltage of the RF automatic gain control apparatus if the detected level of the IF input signal is higher than the reference level.