Constant rise AGC device
申请公布号:US4574252(A)
申请号:US19850715992
申请日期:1985.03.25
申请公布日期:1986.03.04
发明人:SLACK, ROBERT A.
分类号:H03G3/20;(IPC1-7):H03G3/20
主分类号:H03G3/20
摘要:The invented device provides automatic gain control (AGC) of incoming signals over a large dynamic range of input levels with a constant rise time. The constant rise AGC device includes a primary AGC loop for receiving the incoming or input signal and splitting the input signal to input and output components of the primary AGC loop. The input signal to the input component is processed within the primary AGC loop to control the gain of the input signal at the output component of the primary AGC loop. The primary AGC loop has a slow detector. A secondary AGC loop is provided within the primary AGC loop, and this secondary AGC loop includes the aforementioned input component and has its output connected to the slow detector. The secondary AGC loop has a fast detector for preventing self-imposed saturation. With this arrangement the secondary AGC loop can be utilized to provide a constant AGC buildup signal for any input signal which is greater than a predetermined dB range, and the remainder of the primary AGC loop, which receives the constant AGC buildup signal from the secondary AGC loop, can be optimized for desired rise and fall times so that the latter' s output signal can be relatively unaffected by interference bursts, signal gaps, and fading in the input signal.