共集-共基放大电路高频响应的理论分析和仿真

The Theoretical Analysis and Simulation of High Frequency Response of Common Collector and Common Base Amplifier Circuit

借助EWB软件中的受控源模型,构建了共集-共基组合放大电路的高频简化等效电路,直接启动仿真后得源电压增益、幅频特性、截止频率,与s域建立节点电压方程,运行MATLAB后的结果完全一致。利用MATLAB编程的便捷性,分别绘制了源电压增益的幅度与共集、共基组态集电结电容间的关系曲线,得到共基组态的结电容对频响影响更大的结论;对容抗取极限,比较了共集、共基和组合电路的幅频特性,验证了多级放大器的截止频率与各级截止频率间的关系式,为分析各种放大电路的频率响应提供了一种新的处理方法。

High frequency equivalent circuit of CC-CB amplifier circuit is built with controlled source ofEWB software, the gain of source voltage, the amplitude frequency response, and the cutott irequency are derived with simulation, the results are similar with those of building voltage equations of voltage in S domain and solve them by MATLAB. With the convenience of MATLAB of programming, the relation curve between the amplitude of gain of source voltage and the capacitance of collector ]unction for CC and CB combination circuits, the conclusion was made that the capacitance of ]unction of CB combination circuit is larger. The amplitude frequency character of CC, CB and CC-CB combination circuits are compared under condition that the value of capacitance impedance is limited, the relationship between the multi-stage amplifier with multi-stage cutoff frequency is verified, and a new method is proposed to analyze the frequency response of different amplifier circuits.