| 摘要 |
PROBLEM TO BE SOLVED: To obtain optimum outputs for both CW waves and burst waves in the same circuit by providing an automatic gain control circuit with a peak hold circuit that almost holds the peak value of a signal inputted to the circuit. SOLUTION: An automatic gain control circuit is provided with a peak hold circuit which almost holds the peak value of a signal inputted to the circuit. Then, the automatic gain control circuit is further provided with an amplifier circuit 31 amplifying a signal inputted to the peak hold circuit, and the peak hold circuit consists of a diode 34 where a signal is transferred only in a forward direction, a charging and discharging circuit 32 charging and discharging a capacitor on the basis of an input signal and a high impedance buffer 35 whose output is connected to the circuit 31. By constructing such a configuration, it is possible to perform fast charging to the circuit 32 when inputting burst waves. Further, it is possible to realize a peak hold circuit with a simple circuit configuration because this device can be constructed just by adding a simple circuit to a conventional circuit configuration. |
