通常应用的反馈放大器的计算方法是以经典反馈理论为基础的。经典反馈理论要求所讨论的反馈电路可以截然区分为主放大器和反馈网路两个独立部分,这往往是难以作到的。经典反馈理论只考虑了反馈网路对信号的反馈作用,忽略了反馈网路对主放大器的负载作用和反馈网路对信号的正向传输作用,因而具有很大的局限性。后来提出的“电路行列式”方法和“信号流图”方法克服了这种局限性,但是这些方法都比较繁 Commonly used feedback amplifier calculation method is based on the classical feedback theory. The classical feedback theory requires that the feedback circuit in question be distinctly divided into two separate parts: the main amplifier and the feedback network, which is often difficult to do. The classical feedback theory only considers the feedback effect of the feedback network on the signal, ignores the load effect of the feedback network on the main amplifier and the positive transmission effect of the feedback network on the signal, and thus has great limitations. Later proposed “circuit determinant” method and “signal flow graph” method to overcome this limitation, but these methods are more complex