Leeson feedback mechanism question

[yefj]

TL;DR

leeson mechanism reccomendation question

Hello,I want to created th following system.From the articles I see that we input noise to the amplifier then the noise gets amplified and we compare thefeedback from the output(s11) to the noise.
few questions:
1. where is the comparation of the feedback in the topology below.
I cant see here the feedback.
2. at resonance we have phase of 0,what is the effect of the feedback here?
Thanks.

 

[Tom.G]

The inductor, L_Ser is the feedback element in making the transistor circuit a negative-impedance stage. The resonant circuit on the gate determines the frequency. Although unstated, I suspect that the actual feedback is the transistor's internal stray coupling. This is based on my reading of pgs. 2 thru 4 of your attached PDF file.

This is way outside my usual field so this reference will page @berkeman, who I believe is a ham radio operator that may have a better (and more accurate!) explanation.

Cheers,
Tom