FAQs from Rohde & Schwarz

ZNB - Calibration Validation always fails

Description

I have done a calibration and now I want to validate it with an automatic calibration kit. But it always fails. What is wrong?

Resolution

The "Basic Mode" of the calibration validation function measures S11, S22 etc (depending which ports have been calibrated) of the standards Open, Short and Match.
At the areas where the reflection attenuation of the Match standard is very high, the measurement result is noisy and exeeds the tolerance of + / - 0.2 dB.

For the validation please use the "Advanced Mode". Here you can do the validation for each standard seperately.
Just check if the validation is in tolerance for "Open" and "Short" standards. Then you can be sure that the calibration is correct.
Please do not use the "Match" standard for the validation.