We at METAS are using the following process to implement a new E-Cal unit to the VNA Tools II calibration standard database:
1) Calibrate the VNA using a mechanical calibration kit with known standard definitions and uncertainties (Agilent Model Standard or Databased Standard).
2) Characterize the E-Cal unit by measuring each impedance state. This can be done in the Measurement Journal using in the Add Measurement, Measurement Series file dialog. Mode: Ecal.
This will result in error corrected data of each E-Cal impedance state including the uncertainties and the correlation information.
3) Use the ‘New Database Standard Wizard’ to add each impedance state of the previously characterized E-Cal unit as databased standard in the VNA Tools II calibration standard database.
Now you can use your characterized E-Cal unit like any other calibration kit.
Select the optimization calibration if you want to use an over-determined calibration using all impedance states of the E-Cal unit.
For N-port calibrations: For an insertable measurement setup we do measure the direct thru connection (mating the test port connectors directly together) without using the E-Cal unit. For an non-insertable measurement setup we will measure the E-Cal thru state and then define this Thru measurement as Unknown Thru in the Calibration Config, Definition path.