5、周期单位冲激序列的FT Impulse-train 8.0定u-0-立em7 00 n=-c0 1n=-g0 00 FT[f(t)]=2π ∑6(o-no,) T n=-o0 00 F(o)=FT[,()]=0∑6(o-no) n=-005、周期单位冲激序列的FT Impulse-train 1 1 1 1 1 1 ( ) ( ) . jn t jn t T n n n n t t nT F e e T ( ) 1 [ ( )] 2 1 1 n T FT f t n 1 1 1 ( ) [ ( )] ( ) T n F FT t n