什么是“小信号”

What is Small Signal

首先讨论了在电路原理课程中讲授非线性电阻电路分析的必要性,随后探讨了非线性电阻电路的小信号分析方法。在给出当前教材对于小信号的普遍定义之后,用3个简单的例子讨论了这种定义方式存在的问题,从误差的角度深入探讨了怎样的信号才能够称之为小信号这一重要的概念性问题,给出了比较严格的小信号定义。

This paper discusses the necessity of teaching nonlinear resistive circuits in the course of Principles of Electric Circuits first. Then the small signal analysis method is presented. After given the classic definition of the small signal in the current textbooks, the authors discuss the shortcomings of this kind of definition by 3 simple examples. The strict definition of the small signal, which is the key concept in nonlinear resistive circuits analysis, is illustrated by using the concept of error analysis.