Filter Design by Impulse Invariance G U Digital Signal Processing--IIR Digital Filter Design h(n)=ha(nT) Ha(s)=L[ha(t)] H(Z)=Z[h(n)] a(=之 4 i=1 s-Si h,()=之Aeu(t), u(t) i=l hn)）=ha(nT)=∑Aern)）=∑A(er)y”un) i=l i=l 上游充通大Digital Signal Processing—— IIR Digital Filter Design Filter Design by Impulse Invariance h(n)=ha(nT) Ha(s)=L[ha(t)] H(z)=Z[h(n)] ∑= − = N i i i s s A Ha s 1 ( ) ∑= = N i s t a i h t Ae u t u t i 1 ( ) ( ), ( ) ∑ ∑ = = = = = N i N i s T n i s nT i h n ha nT Ae u n A e u n i i 1 1 ( ) ( ) ( ) ( ) ( )