Relationship between z-transform and Fourier transform Express the z in polar form as X(z)=∑x[n]z” =X(rem）=∑(x[nlr"）emm n=-o0 z-transform is the Fourier transform of the product of xn and( (the exponential sequence ) Ifr=Z-l,X(Z)→X(eo) 66 ◆Express the z in polar form as Relationship between z-transform and Fourier transform j Z = re ( ) (   ) j n j n n X e re x n r    − = − − = =  ◆z-transform is the Fourier transform of the product of and (the exponential sequence ). x n  n r − If X Z r Z = = 1, ( ) ( )   n n X z x n z  =− − =  ( ) j X e 