Cascaded amplifier AF and bias calculations

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Mancho

Joined Jul 20, 2008
3
Hello everyone, here is my lab work and its tasks. I’ve done part of them, but I’m stuck at some points:confused:. I’d be grateful if anyone can help.

I’m asked:
1.to do bias calculations for transistors Q1 and Q2 and to find IQC1 and IQC2.
2.to calculate AF by t parameter analyses.

please find schematics and my solutions in attached PDF.


1. I calculated collector currents for each transistor by changing with its Thevenin equivalent, assuming both independent from each other. But I’m not sure if I could consider Q2 independent because it’s driven by Q1. How changing with Thevenin is influenced by the ouput of Q1 and by the feedback?

2.As for AF, first I tried to draw an equivalent circuit for the given one, but I got confused with so many resistances and something tells me it’s incorrect. I can’t go further because I don’t know how to draw it in a right way
 

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