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Is it possible to apply a calibration without a Power Cal to a channel with a Differential IQ measurement class

Question asked by ChrisSight on Aug 19, 2020
Latest reply on Aug 21, 2020 by daras

Hi Everyone,


Thank you to everyone who takes the time to read this.



The differential IQ measurement class seems to need a Power Cal to apply a calibration, is this a true statement? Is there a way to apply a SOLT calibration to this class without a Power Cal? 



My setup (which measures RFICs on a wafer) is using the N5245A with firmware A.10.65.08, the ports are connected to a probe card where I am starting to use an ISS for calibration. We were excited about this as it meant for calibrations down to the probe tips. And no more extra time connecting to a power meter/ ECAL. Usually, I went through calibration with a "standard" measurement class (which included a power cal) and applied that calibration to all other channels (some of which are differential IQ, I'm measuring THD in a similar way described here: ).

However with the ISS it's impossible to make this power cal, I went and made my own CalKit and used the standard measurement class as usual, but I can't apply the calibration to my channels with a differential IQ measurement class. I get an error that says;

the correction will turn off and trying to turn it on,  will just yield error 612 again. 

I've tried to run calibration with only the Differential IQ channel, and during the calibration, I have this option configured:

but this page still pops up:

Leading to this:


I'm not sure if this part of the problem.

When trying to calibrate a standard class I can see my Cal Method is 4 port (I've edited out the DUT connector and Cal Kit names):

But calibrating a differential IQ class, the method is unknown Thru: