The multistage amplifier circuit of Figure Q.2(b) have the following parameters: Q 1 and Q 2 : = 200, V BE = 0.7 V,

The multistage amplifier circuit of Figure Q.2(b) have the following parameters:
Q₁ and Q₂ : β = 200, V_BE = 0.7 V, V_T = 26 mV , V_A = ∞
Given that I_CQ1 = 2 mA and V_CEQ1 = 2 V.

(i) Determine the value for R_B4. List the assumption/approximation made in the analysis.

(ii) Sketch and label the small-signal hybrid-π equivalent circuit at midband frequency range.

(iii) Calculate the small signal hybrid-π model parameters: g_m and r_π for Q₁ and Q₂. Then, determine Z_i2 and Z_o.

+15 V Re 3.3 ka 10 k2 100 k2 C4 Rs 100 2 RL 10k2 50 k2 RB4 RE 2 ka Z, Figure Q.2(b)