Problem 5.45(b): For the circuit below, assume that $Q_1$ and $Q_2$ are identical except for having different widths, $W_1$ and $W_2$. Let $V_t = 0.5 V$, $k_n = 0.4 mA/V^2$, $L_1 = L_2 = 0.36 \mu m$, $W_1 = 1.8 \mu m$, and $\lambda = 0$.
Find the value of $R_2$, in $k\Omega$, so that $Q_2$ operates at the edge of saturation with a current 0.6 mA. Assume that R is selected so that current in $Q_1$ is $100 \mu A$.
$V_{DD} = 1.8 V$
