| 摘要 |
PURPOSE:To make leading-in of the automatic gain control device stable, sure, and high-speed, by making the input signal range optimum by the amplification degree corresponding to the input signal level and by holding the control voltage of the amplifier in a certain level for no input. CONSTITUTION:Level detector 8 is operated according to output (b) of carrier detector 5 to detect the maximum level of input singal (a) and assignes it to a prescribed amplifier of amplifier group 9 for amplification or attenuation of signal (a), and the selected amplifier of amplifier group 9 amplifies or attenuates signal (a) to generate input signal (a') and outputs this signal. Oscillator 6 generates the signal of a prescribed level or less and is operated in respons to signal (b) of detector 5. Consequently, adder 7 sends only one of input signal (a) of the prescribed level or more and initializing signal (e) to voltage control amplifier 1. |
