基于微变等效电路的差分—共基负反馈放大器的仿真与分析

The Simulation and Analysis of Differential Common Basis Negative Feedback Amplifier Based on Micro-change Equivalent Circuit

在使用稳压管较好解决直流电平配置与输入信号有效放大的基础上,设计了差分-共基电流串联负反馈放大电路。经静态电流计算得晶体管交流等效电阻,按晶体管小信号模型得微变等效电路。对等效电路开、闭环仿真结果与理论计算相对误差分别是0.61%和1.01%,吻合很好,说明分析方法正确。对基本电路仿真与理论的相对误差分别是2.89%和0.69%,基本一致。另外从等效电路和基本电路仿真中都得到反馈电压,求得反馈系数、闭环增益,它们也与理论计算相符合,验证了反馈放大器中基本关系式。

Based on DC level configuration and amplify input signal,Bg using voltage- regulater-tube. current- series negative feedback circuit with differential common basisis designed in the paper. AC equivalent resistance is derived by calculating the quiescent current,micro- change equivalent circuit is achieved by small signal model of transistor. The relative error between the simulation results and theoretical values of open and close loop circuits are 0. 61% and 1.01% respectively. The results demonstrate that they are in good agreement,and the correctness of the method is proved. The relative error between the simulation results and theoretical values for basic circuit are 2. 89% and 0. 69%,they are almost the same. In addition,the feedback voltage,the coefficient of feedback and the gain of closed- loop are also derived from simulation of micro- change equivalent circuit and basic circuit,they are consistent with the theoretical calculation,and the basic formulation of feedback amplifier is proved.