CAJ | 학술논문

设计了自动增益控制电路，能够使放大电路的增益自动随信号强度的变化而调整。该电路通过采用改变BJT的直流工作状态来改变BJT的电流放大系数β，实现电阻分压以及改变JFET的栅源电压来控制放大器电阻的大小。设计的自动增益控制电路阐述了BJT分压、JFET变阻以及AGC电路的工作原理，实现了可控增益范围大约为40dB，对现实教学和应用都有很好的借鉴意义。
설계료자동증익공제전로，능구사방대전로적증익자동수신호강도적변화이조정。해전로통과채용개변BJT적직류공작상태래개변BJT적전류방대계수β，실현전조분압이급개변JFET적책원전압래공제방대기전조적대소。설계적자동증익공제전로천술료BJT분압、JFET변조이급AGC전로적공작원리，실현료가공증익범위대약위40dB，대현실교학화응용도유흔호적차감의의。
The paper designs an automatic gain control (AGC) circuit, enabling the gain of amplifier circuit automatically adjusted with the change of signal strength. The circuit changes the current amplification coefficient β of BJT by means of changing the DC working state of BJT, so as to realize the partial pressure and control the resistance of the amplifier by changing the S gate voltage of JFET. The designed AGC circuit describes BJT partial pressure, JFET variable resistance, and the working principle of AGC circuit. The obtained controllable gain range is about 40dB, and the system has very good reference significance for the practical teaching and application.