Do you disregard that I have a couple PMs between 72 deg to 75 deg when I use a load less than 0.5A or greater than 1.5A on the VRM. So for a 1A load, I see ~66 deg PM.
Also, is there a method you use to calculate the gain margin with the NISM software setup? If not, how do you calculate this or do you when you are using the NISM software on the (respective) VNA?
NISM requires real and imaginary terms, so that's the best it can do. Better than 71 degrees? Pat yourself on the back for a job well done.
We're actually measuring Stability margin and solving it as equivalent phase margin. We can do it similarly for gain margin.
Bode plots neglect stability margin, which is a huge deficiency in the assessment.
The Bode 100 provides phase margin, gain margin and stability margin.