$3.$ The common$-$source stage should have a gain of $20$ dB under a bias current of $1$ mA$.$

Assume VTHN $=$ VTHP $=0\mathrm{.}5$ V$,$nCox$=200$A$/$V$2$

$,$pCox$=100$A$/$V$2$

$,$ $1=0\mathrm{.}1$ V$-1$ and

$2=0\mathrm{.}15$ V$-1$

$.$

$($a$)$ Determine the required value of $($W$/$L$)1.(5/100)$

$($b$)$ If $($W$/$L$)2=30/0\mathrm{.}18,$ determine the required VB$.(5/100)$