4.112 For the common-emitter amplifier shown in
Fig. P4.112, let $V_{cc} = 9V$, $R_1 = 27 k\Omega$, $R_2 = 15 k\Omega$, $R_E = 1.2 k\Omega$,
and $R_C = 22 k\Omega$. The transistor has $\beta = 100$ and $V_A = 100 V$.
Calculate the dc bias current $I_C$. If the amplifier operates
between a source for which $R_{sig} = 10 k\Omega$ and a load of
$2 k\Omega$, replace the transistor with its hybrid-$\pi$ model, and
find the values of $R_{in}$, and the overall voltage gain $v_o/v_{sig}$,
and the current gain $i_o/i_i$.
