Calibrating a vector network analyzer (VNA) with different connectors on each port

Question

Do you have any solution for calibrating a vector network analyzer (VNA) with different connectors on each port?

In my case, SMA and APC-7 connectors.

Answer

To make a full two-port calibration with different connector types on each port, you use the UOSM calibration routine. U stands for Unknown Through.

You need a calibration kit for the SMA, a calibration kit for the APC-7 and an adapter from the SMA to the APC-7.

For each port, you make the OSM calibration with the corresponding calibration kit. For the Unknown Through calibration, you use the adapter.

After this, you have a fully two-port calibrated VNA