Filter Design by Impulse Invariance Digital Signal Processing--IIR Digital Filter Design (s)=[[h (t)>(t-nT)le-"dt n=-00 =∑h.u)δt-nI)ed =∑h,(nT)ew7 H(a)=∑h(n)zn n=-00 ST s plane ~z plane z=e 上游充通大粤Digital Signal Processing—— IIR Digital Filter Design Filter Design by Impulse Invariance ∑ ∑ ∫ ∫ ∑ ∞ =−∞ − ∞ =−∞ ∞ −∞ − ∞ −∞ − ∞ =−∞ = = − = − n nsT n st st n h nT e h t t nT e dt H s h t t nT e dt ( ) ( ) ( ) ( ) [ ( ) ( )] ˆ a a a a δ δ ∑ ∞ =−∞ − = n n H(z) h(n)z sT s plane ~z plane z = e