AGC device satisfying sufficient impedance matching characteristics and linear AGC characteristics at the same time

摘要

A low-cost AGC device in which sufficient impedance matching characteristics and linear AGC characteristics are provided. The AGC device is provided with a linear calibration circuit. The linear calibration circuit calibrates the control voltage (x) from the control voltage generator circuit and outputs the calibrated control voltage (w) to the variable gain amplifier circuit. The above-mentioned calibration is a calibration to make the change of the decibel value of some AGC gain about the control voltage (x) linear.