Question
When I try to initiate the calibration, I get following warning: “Active cal kit or cal unit does not contain all standards needed for selected cal procedure.”
VNA calibration warning that the active cal kit does not contain all needed standards
“Active cal kit or cal unit does not contain all standards needed for selected cal procedure.”
Answer
Before the calibration, user is required to select one mechanical cal kit during manual calibration so that the VNA knows upfront which will be the calibration kit to be used. For a ZNB20 (FW 3.20 ) this looks as below after presetting the unit.
The default cal kit is ZV-Z135 since ZNB20 comes with 3.5 mm male ports. This can be verified in the ZNB family specifications datasheet.
| Impedance | 50 Ω | |
| Test port connector | R&S®ZNB4 | N female |
| R&S®ZNB8 | N female | |
| R&S®ZNB20 | 3.5 mm, male, ruggedized | |
| R&S®ZNB40 | 2.92 mm, male, ruggedized | |
| Number of test ports | R&S®ZNB4 | 2 or 4 |
For this reason, the gender in the cal menu has been automatically set to male. This goes in reference to the test port gender. In addition, one can verify the cal kit standards definition in the VNA menu as per below,
Since the user may need to connect extra cables and/or connectors to reach his device under test, the VNA interface gives the chance to play around with the test port gender accordingly. However, one needs to consider that if the test port gender is set to male, the VNA expects to find female standards in the pre selected cal kit. The opposite if the gender is set to female. This will work well for above presented scenario since all standards are available. But this may not always be like that since some users only have a set of female or male standards. In this case the test port gender needs to be set accordingly with the cal kit definitions, otherwise below warning may appear and the calibration is then not allowed where a cal kit containing only female standards is selected.
At this point the solution is to change the test port gender and consider additional cables and connectors to reach out the DUT. In some scenarios this may appear as a mishandling of the test port gender directly available on the front panel of the VNA. But this is not the case, since one needs to remember the multiple different situations which may appear while connecting one VNA to all the different DUTs available in the market.
