Colpitts oscillator and transconductance value

Discussion in 'Homework Help' started by Iza Soliwoda, Feb 17, 2016.

  1. Iza Soliwoda

    Thread Starter New Member

    Sep 2, 2015
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    Hello! Can you give me a hint to answer this question? This is part of an exam task. The first part was to identify input impedance, which I did.
    "For what values of parameters (gm, I1) circuit can (regardless of the small changes of voltage and current supply and the temperature) generate periodic output voltage signal?" I searched for this whole night and failed to answer it. What I found is that:
    Magnitude criterion for steady-state oscillation at the oscillation frequency f is given by
    |T (f)| = 1
    In order for the oscillations to start and grow, the magnitude of the loop gain T must be greater than unity.
    (I had to translate it from Polish to English, so I hope everything is understandable and sorry for any mistakes :). )
    zadanie_gm.png
     
  2. Jony130

    AAC Fanatic!

    Feb 17, 2009
    3,957
    1,097
    Try to watch this
     
    Iza Soliwoda likes this.
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