obrien135
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Hello,
I tried to analyse a colpitts oscillator based on common emittor small signal model and analyses of feedback / phase changeing network. I don't know if I got the equation for voltage gain in a common emittor amplifier right, my text book is in the basement right now. I have to find it. But the calculations I did are shown on the attached sheet. The question is, how is a phase shift of zero achieved and how do you get a transfer function with a pole that has a real component >= 0 so it will be unstable and therefore oscillate?
I tried to analyse a colpitts oscillator based on common emittor small signal model and analyses of feedback / phase changeing network. I don't know if I got the equation for voltage gain in a common emittor amplifier right, my text book is in the basement right now. I have to find it. But the calculations I did are shown on the attached sheet. The question is, how is a phase shift of zero achieved and how do you get a transfer function with a pole that has a real component >= 0 so it will be unstable and therefore oscillate?