• Bilinear Transformation Method (BLT method) - Relation belween L.T and z.T is $$S = \frac{2}{T} \frac{z-1}{T} \text { os } z=\frac{1+5 T / 2}{1-S T / 2}$$

$H(S)=\frac{2 S-t}{S^{2}-3 S+2}$

design digital filter using BLT method with $T=0.5 \mathrm{s}$

$H(z)=H(S)$

$$S=\frac{2}{T} \frac{z-1}{Z+1}=4\left(\frac{z-1}{z+1}\right)$$ $=\frac{8\left(\frac{z-1}{z+1}\right)-1} {16\left(\frac{z-1}{z+1}\right)^{2}-3 \times 4\left(\frac{z-1}{z+1}\right)+2}$ …