What is the Correct method to find the poles and zeros expressions ? enter image description here

This is a replica circuit method used to calculate loop gain, please only consider the above part. I used pspice to find the bode plot of the given circuit, I found that there is three poles since phase graph approaches 270. However, I tried to find poles expressions by hand and I was able to recognize only one pole which is wp = 1/(RE1*CE1). I didn't take Cpi, Cu, and Ccs into consideration yet . What is the correct way to find poles? I think inspection, and miller approximation doesn't work to find other poles

  • \$\begingroup\$ Why do you wish to know what they are? \$\endgroup\$ – Andy aka Dec 19 '18 at 18:39
  • \$\begingroup\$ I want to find out the transfer function by hand \$\endgroup\$ – Mohan Dec 19 '18 at 18:55
  • \$\begingroup\$ But why - you have used a sim and that will likely give a much clearer result than trying the math approach. \$\endgroup\$ – Andy aka Dec 19 '18 at 19:00
  • \$\begingroup\$ Did you consider capacitances in the transistor model? \$\endgroup\$ – Daniel Dec 19 '18 at 19:28
  • \$\begingroup\$ No, I didn't actually \$\endgroup\$ – Mohan Dec 19 '18 at 19:34

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