并联负反馈放大器下限截止频率f_(Lf)解析式的多样性

An analytical formula variety of the lower cut-off frequency of amplifier with parallel negative-fee

摘要: 根据基尔霍夫定律、交流等效电路,导出了并联负反馈放大器下限截止频率fLf的解析关系式.新关系式能直观、准确描述fLf与电路参数间的函数关系;显示出fLf解析式会因电路级间耦合电容的多少而有不同形式;证明了原关系式给出的实际上是一种模糊关系式.

Abstract: A new formula of the lower cut-off frequency f_(Lf) of amplifier with parallel negative-feedback was given by equivalent circuit and Kirchoff's law.The functional relationship between f_(Lf) and parameters of circuit can been described accurately by the new formula obtained.It has been proved that the method of block diagram doesn't give expression to kirchoff's law of circuit.