具有自动增益控制的射频振荡器稳定性分析

摘要

This paper designs a circuit with automatic gain control (AGC) to stabilize the output amplitude of RF power oscillator. However,after adding the AGC negative feedback circuit,the output amplitude of RF power oscillator is more unstable because of the self-oscillation of the circuit. The paper gives out a reasonable solution,which keeps the circuit system stable. It adjusts the transistor's emitter resistor of the feedback circuit after analyzing the transfer function of the whole circuit system,which achieves the purpose of stabilizing output amplitude of the RF power oscillator.%设计了一个具有自动增益控制(AGC)的电路采稳定射频功率振荡器的输出幅度,然而在加入AGC负反馈环路之后,该环路可能会产生自激振荡,使得振荡器输出的幅度更加不稳定.通过对整个电路系统传递函数的分析,采用调节反馈电路中三极管发射极电阻阻值的方法,使该电路工作在稳定的状态,进而达到稳定振荡器输出幅度的目的.