\[f_{\beta}=\frac{\text{g}_{\text{b}}^{\prime} \text{e}}{2 \pi\left(\text{C}_{\text{e}}+\text{C}_{\text{c}}\right)}=\frac{\text{g}_{\text{m}}}{\text{h}_{\text{fe}} 2 \pi\left(\text{C}_{\text{e}}+\text{C}_{\text{c}}\right)}\]
\[f_{\beta}=\frac{\text{g}_{\text{b}}^{\prime} \text{e}}{2 \pi\left(\text{C}_{\text{e}}+\text{C}_{\text{c}}\right)}=\frac{\text{g}_{\text{m}}}{\text{h}_{\text{fe}} 2 \pi\left(\text{C}_{\text{e}}+\text{C}_{\text{c}}\right)}\]