Cascaded amplifier AF and bias calculations

Discussion in 'Homework Help' started by Mancho, Nov 29, 2008.

  1. Mancho

    Thread Starter New Member

    Jul 20, 2008
    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: do bias calculations for transistors Q1 and Q2 and to find IQC1 and IQC2. 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