2000 年上海同济大学信号与系统考研真题 一、术语解释（对标有*号的术语要用表达式举例）（25 分） （1）信号* _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________ （2）信息 _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________ （3）连续信号* _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________ （4）数字信号 _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________ （6）随机信号 _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________ （7）单位冲激函数* 

_______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________ （8）频谱分析 _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________ （9）系统 _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________ （10）数学模型 _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________ 二、（1）简要说明线性系统的基本性质。（10 分） _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________ （2）非线性系统与线性系统的主要区别是什么?（5 分） _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________________________________________ _______________________________________________ 三、（1）写出傅立叶正变换和反变换的基本表达式。 （5 分） 

（3）画图说明傅立叶变换结果的物理意义。（5 分） 四、在图 a 所示的配串联电路上，加有如图 b 所示的激励电压. （1）写出图 b 电压信号的表达式，（5 分） （3） 作出响应电流 i（t）的曲线图。（5 分）