VARIABLE GAIN AMPLIFIER CIRCUIT, OFFSET CONTROL METHOD IN VARIABLE GAIN AMPLIFIER CIRCUIT, WIRELESS RECEIVER HAVING A VARIABLE GAIN AMPLIFIER CIRCUIT, WIRELESS RECEIVING METHOD IN A WIRELESS RECEIVER HAVING A VARIABLE GAIN AMPLIFIER CIRCUIT

摘要

The present invention provides a variable gain amplifier circuit having an offset correction function with less offset variation due to gain switching, and a wireless receiver without deterioration in communication quality due to offset generated in the baseband portion.;In the offset detection mode, the input conversion offset voltage of the variable gain amplifier circuit is input to the offset holding means, and in the signal amplification mode, the input of the variable gain amplifier circuit is subtracted from the input signal to turn off the output of the offset holding means. Perform set calibration. In addition, the offset generated in the baseband portion of the radio receiver is corrected by the offset correction function of the variable gain amplifier circuit, thereby preventing deterioration in communication quality.