Figure$($a$)$ shows a common$-$emitter amplifier and $($b$)$ is the equivalent circuit of the transistor. $r_{}$ and $g_m$ are as follows.

$r_{}=\frac{r_e}{1-{}_0}$

$g_m=\frac{{}_0}{r_e}$

where $r_e=\frac{0\mathrm{.}026}{I_E}$ and ${}_0=0\mathrm{.}99.$ The bias current $I_E$ and lowfrequency input impedance $Z_i$ have been estimated to be $1$ mA

$($a$)$

and $1\mathrm{.}1k,$ respectively. Calculate the higher cut$-$off frequency, numerically.

${22}^2$:$10-1$

Figure$($a$)$ shows a common$-$emitter amplifier and $($b$)$ is the equivalent circuit of the transistor. $r_{}$ and $g_m$ are as follows.

$r_{}=\frac{r_e}{1-{}_0}$

$g_m=\frac{{}_0}{r_e}$

where $r_e=\frac{0\mathrm{.}026}{I_E}$ and ${}_0=0\mathrm{.}99.$ The bias current $I_E$ and lowfrequency input impedance $Z_i$ have been estimated to be $1$ mA

$($a$)$

and $1\mathrm{.}1k,$ respectively. Calculate the higher cut$-$off frequency, numerically.