Exercise 8.3 A current source

a)

An answer:

$$\begin{array}{rcll}{R}_S=\frac{V_{\mathit{GG}}\frac{R_{G2}}{R_{G1}+R_{G2}}-V_T-\sqrt{\frac{2I_D}{k}}}{I_D}& & & \end{array}$$

b)

c)

d)

An answer:

$$\begin{array}{rcll}{r}_{\mathit{out}}=R_S+(1+g_m{R}_S)\cdot r_{\mathit{ds}}& & & \end{array}$$