I'd like to derive an expression for the small signal voltage gain \$A(s)=V_o/V_{sig}\$ that applies in the mid- and low frequency bands. I know that for a CE the voltage gain would be:
\$A_v = -g_mR_c/(1+g_mR_E)\$
Does that mean that \$A(s)\$ could easily be found by simply substituting \$R_E=R_e+1/sC_E\$?

