stability feedback connection physics

[yefj]

Hello,the component shown bellow is supposed to spabilise the gain over frequency range.
Is there some physical explanation i can use to see the this effect in mathematical way?
Thanks.

 

[andre_luis]

Is there some physical explanation i can use to see the this effect in mathematical way?

In simple words, the Drain-Source voltage V_DS is supposed to be the inverse of the Gate-Source voltage V_GS, so any connection among Drain and Gate would act as a negative feedback addition, therefore the above RLC circuit would avoid oscillation at its natural frequency.

 

[yefj]

Hello Andre, the general rule for stability is the barkausen stability criteria as shown bellow.
Here we have a negative feedback ,the only thing i know that when AB=-1 we are going to have oscilations
given the expression bellow Why exactly at resonance frequency of the loop RLC we will get a more stable signal then at other frequencies?

how do i know the beta value in the real circuit?
Thanks.

Barkhausen stability criterion - Wikipedia

en.wikipedia.org

 

[andre_luis]

You surelly know that a negative feedback means that there will hava a compensation on the input stage due to the output stage; considering that the series RLC circuit have its smallest impedance ( the higher β ) at its resonant frequency, it is expected that most of the signal component at this frequency will be damped.