例求x(n)=Rv(n)的z变换及其收敛域 00 解:X(z∑x(n)"=∑Rv(m)z n=-o∞ n=-o∞ 2- n=n 1-9 h=0 -1-z习 n,→o时须满足9<1 2W-1 z-(z-1) tjlm[z] 2π1 零点:三=eNr=1N-1 Refz] 极点:z=0(N-1)阶 Roc:0<z≤o1 ( ) ( ) z N 例:求 的 变换及其收敛域 x n R n Re[ ]z j z Im[ ] 0 X(z)= ( ) = ( ) n n N n n x n z R n z 解: 1 0 = N n n z 2 1,..., 1 r j N z e r N 零点: 极点: ( )阶 z N 0 1 Roc z : 0 2 1 2 1 1 1 n n n n n n q q q q 1 1 1 N z z 2 n q 时须满足 1 1 1 ( 1) N N z z z