P$10\mathrm{.}3$

For the circuit shown in Fig. P$10\mathrm{.}3.$ Assume $\backslash (\backslash$mathrm$\{$M$\}\_\{1\}\backslash )$ is in saturation mode and $\backslash (\backslash$mathrm$\{$Q$\}\_\{1\}\backslash )$ is in FAR. Do not ignore $\backslash (\backslash$mathrm$\{$r$\}\_\{\backslash$mathrm$\{$o$\}\}\backslash )$ of the transistors.

a$)$ Draw the small signal model. The transconductance and $\backslash (\backslash$mathrm$\{$r$\}\_\{\backslash$mathrm$\{$o$\}\}\backslash )$ of the two transistors are different.

b$)$ Write the expression for the low frequency small signal gain.