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Re: Question: Is it possible to use calibration imperfections to detect the quality of calibration standards??? #calibration


 

Well, the delays did not work as expected.
So I'l formulate my tuning question a bit more to the point.

The green line in attached picture shows the outcome of this formula "phase(S11open) - phase(S11short) - pi" of a 1 meter coax cable versus the frequency (0.5 till 900MHz)
The phase is unwrapped to avoid discontinuities.
The line should be flat on 0 independent of the frequency but it is not. 0 means the S11open and S11short are exactly opposite on the smith chart

What parameter of a generic VNA calibration set or bridge imperfection model will allow tuning away the green error at higher frequencies? So the parameter should have an increasing impact on phase errors on higher frequencies and not on amplitude or low frequency phase errors?

As you can see the tuning for the amplitude is progressing rather well. The blue lines show abs(S11open) and abs(S11short)

And I would be most happy if someone can explain how to modify global variables (without a "clear all") from a function as I fail to find how?????

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