Chapter 7, Problem 7.14EP

Consider the common−base circuit in Figure 7.64. The transistor parameters are $\beta =100$ , $V_{BE}\text{(on)=0}\text{.7V}$ , $V_A=\infty$ , $C_{\pi }=24\text{pF}$ , and $C_{\mu }=3\text{pF}$ . (a) Determine the upper 3dB frequencies corresponding to the input and output portions of the equivalent circuit. (b) Calculate the small−signal midband voltage gain. (Ans. (a) $f_{H\pi }=223\text{MHz}$ , $f_{H\mu }=58.3\text{MHz}$ , (b) $A_{\upsilon }=0.869$ )

Figure 7.64 Figure for Exercise Ex 7.14