李萨如图形在系统频率特性测量实验中的应用

Application of Lissa-jou's figure in system frequency characteristic measuring experiment

根据李萨如图形的形成原理,分析了李萨如图形在2个频率相同的正弦信号输入下图形大小及形状与输入信号的幅值和相位的关系,详细介绍了用李萨如图形法测量系统频率特性的原理,并举例说明了该测量方法在实验中的用法。实验证明,该方法简单方便,易于掌握和实现,不仅有助于学生理解和掌握课堂内容,也为以后从事相关研究工作打下了基础。

According to the forming principle of Lissa-jou＇s figure, this paper analyzes the relationship between the size and shape of Lissa-jou＇s figure and the amplitude and phase of input signal, under two sinusoidal sig nal with identical frequency, then introduces the principle of the method using Lissa-jou;s figure to measure system frequency characteristic, and at last illustrates the usage of the measuring method in experiments. The experimental result proves that this method is simple and convenient, easy to grasp and implement, can not on ly help the students to understand and grasp the classroom teaching content, but also lay a foundation for the future to engage in related research work.