AUTOMATIC GAIN CONTROL CIRCUIT

PURPOSE:To obtain a stable AGC output by devising a control circuit such that the circuit is not in response to the abnormal fluctuation of an input signal level. CONSTITUTION:The fluctuation pattern of a signal inputted to a reception circuit is compared with an abnormal fluctuation pattern stored in advance and when both patterns are similar by a prescribed quantity or above a control signal in response to a normal signal level is generated and fed to a variable gain amplaifier 1 and when both patterns are not similar by a prescribed quantity or above, a control signal in response to the level fluctuation of the input signal is generated to control the gain of the variable gain amplifier 1.