清华大学信号与系统34典型非周期信号频谱ppt课件

单边指数信号)0(0)0()(ttetft)0(1)()(jdtetfFtj221)(F)()(arctg f(t)t0)(F1213)(0022双边指数信号)()(tetft222)(F0)(f(t)(F0t0矩形脉冲信号)(0)()(22ttEtf)()sin()sin()(222222/2/SaEEdtEeFEtj)()(2SaEF)()(0)()1(4)12(2)12(24nnnn f(t)t0)(F24622)(EE符号函数)0(1)0(1)sgn()(ttttf).sgn(lim)(lim)(010taaaettftfjajFFaa22lim)(lim)(220102)(F)0()0()(22 f1(t)(1F10ta-a 0 tSgn(t)+1-1)(F)(22tae0a3.5 冲激函数傅立叶变换对1)()(dtetFtj1t0)(t)(F21)(21)(1deFTtj1)(tf10t2)(200 冲激偶的傅立叶变换dettj21)(dejtdtdtj)()(21jtdtdFT)(nnnjtdtdFT)()()()(2)(tdtdjtFTnnnn1)(tFT)sgn()(2121ttujtuFT1)()()(F u(t)0t03.6 阶跃信号的傅立叶变换 作业