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I am trying to implement a current mirror as part of a bias circuit for a RF amplifier. I want to do a transfer function of the bias circuit since it creates a loop from the amplifier fet drain to gate. In order to make sure that i dont get any instabilities i want to find the poles from the transfer function.

I have converted the fet amplifier and one of the pnp transistors from the current mirror into small signal models. I have a small signal rf circuit as shown in the drawing.

Any help is much appriciated.

Edit: Alright after being suggested to provide some more of my results i have uploaded some new pictures of what i have done. The above question remains the same, i have a hard time going all the way to a finished transfer function. I do not really know what to do.

I have uploaded the initial schematic of which i want to find the transfer function. I have uploaded a reworked schematic of the loop going from the drain of the Fet to the gate. I have made 4 current meshes, which gives me 4 current equations. I know current3 from the current source. I have made som voldtage division equations for v1 v2 and vg. Solving the system of equations gives me something very ugly and big, which leds me to think something is wrong.

Schematic

Loop

current meshes

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    \$\begingroup\$ Please try to show what you have accomplished so far. Have you tried writing out the nodal equations for this circuit? You are asking for a very specific solution which would require significant work to do, which is unlikely to be worth it for users. \$\endgroup\$ Commented Mar 31, 2018 at 12:50
  • \$\begingroup\$ Alright thank you very much for your comment loudnoises. I have tryed to do as you said, in order for other users to see what i have achieved so far. \$\endgroup\$ Commented Apr 3, 2018 at 20:06

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