Two-Stage BJT Amplifier Homework: Solving for Input Resistance and Voltage Gain

[Alkozy]

Homework Statement

see pic in the attachment
beta = 100

Homework Equations

R_input=R_th
V_input=V_TH
i_B= i_c/beta
I_E=i_c /alpha
i_B=i_E/(beta+1)
g_m=I_C/V_T
A_vo=-g_mR_C
A_v=-g_m(R_C||R_L)
G_v=-Beta[(R_C||R_L)/R_sig+(beta+1)r_e
r_e=alpha/g_m

The Attempt at a Solution

solving each stage separately. First DC analysis. open all Capacitors.
V thevinin can be obtained by voltage divider = 2.88 v
R input = 31.97 K ohm
loop between the base and emitter
2.88-i_B (31.97k)-0.7-i_B(beta+1)(3.9k)=0
I have attached a pic of my attempt to solve it. please see attachment 2

i couldn't complete the solution

 

[NascentOxygen]

There is an important "+" sign missing from your first handwritten equation, i_B = 2.88 (31.97k ...

This is something you would have readily discovered by repeating your analysis from scratch. Often that is the most expedient course, when trying to identify ones mistake.