For a common-emitter amplifier shown in the below figure, let $R_{sig} = 5 \text{ k}\Omega$, $R_{B1} = 33 \text{ k}\Omega$, $R_{B2} = 22 \text{ k}\Omega$, $R_E = 3.9 \text{ k}\Omega$,
$R_C = 4.7 \text{ k}\Omega$, $R_L = 5.6 \text{ k}\Omega$, $V_{CC} = 5 \text{ V}$. The dc emitter current can be shown to be $I_E \approx 0.3 \text{ mA}$, at which $\beta = 120$.
Find the input resistance $R_{in}$ and the midband gain $A_M$.
If $C_{C1} = C_{C2} = 1 \text{ }\mu F$ and $C_E = 20 \text{ }\mu F$, find the three short-circuit time constants and an estimate for $f_L$.