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I am trying to build up a phase shift oscillator using a N Mosfet.
The circuit diagram of such oscillator is:
The AC equivalent of this circuit will be:
By writing KCL for every node of the circuit we end up with these equations:
\[ g_{m}V\pi+\frac{V_{B}}{R_{d}}+\frac{V_{C}}{R_{1}}+\frac{V_{D}}{R_{1}}+\frac{V_{E}}{R_{1}} =0 \]
\[ g_{m}V\pi-sC_{1}(V_{C}-V_{B})+\frac{V_{B}}{R_{d}}=0 \]
\[ sC_{1}(V_{C}-V_{B})+\frac{V_{C}}{R_{1}}-sC_{1}(V_{D}-V_{C})=0 \]
\[ sC_{1}(V_{D}-V_{C})+\frac{V_{D}}{R_{1}}-sC_{1}(V_{E}-V_{D})=0 \]
\[ \frac{V_{E}}{R_{1}}+sC_{1}(V_{E}-V_{D})=0 \]
From the above set of equations we get:
Vc=0
So now what do I have to do to find the resonant frequency and the feedback gain?
The circuit diagram of such oscillator is:
The AC equivalent of this circuit will be:
By writing KCL for every node of the circuit we end up with these equations:
\[ g_{m}V\pi+\frac{V_{B}}{R_{d}}+\frac{V_{C}}{R_{1}}+\frac{V_{D}}{R_{1}}+\frac{V_{E}}{R_{1}} =0 \]
\[ g_{m}V\pi-sC_{1}(V_{C}-V_{B})+\frac{V_{B}}{R_{d}}=0 \]
\[ sC_{1}(V_{C}-V_{B})+\frac{V_{C}}{R_{1}}-sC_{1}(V_{D}-V_{C})=0 \]
\[ sC_{1}(V_{D}-V_{C})+\frac{V_{D}}{R_{1}}-sC_{1}(V_{E}-V_{D})=0 \]
\[ \frac{V_{E}}{R_{1}}+sC_{1}(V_{E}-V_{D})=0 \]
From the above set of equations we get:
Vc=0
So now what do I have to do to find the resonant frequency and the feedback gain?
