As discussed above, the type A extraction uses exactly the same procedure and algorithm as adapter removal. Instead of directly modifying the calibration to remove the effects of the adapter/fixture, however, the S-parameters of the adapter/fixture are exported to an S2P file for later de-embedding or other uses. The reference plane diagram is repeated below for convenience. Two full 2-Port calibrations are required, one with the adapter on Port 1 (so the cal is between 1’ and 2) and one with the adapted on Port 2 (so the cal is between 1 and 2’).
Adapter Removal Block Diagram
1. Test Port 1
2. Test Port 2
3. Port 1 Test Cable
4. Port 2 Test Cable
5. Original Reference Plane 2’, when adapter is connected to Port 2 Test Cable
6. Original Reference Plane 1’, when adapter is connected to Port 1 Test Cable
7. Adapter to be calibrated
The calibrations are performed and then the setups saved typically as an active channel CHX file type. The extraction dialog is shown below where these files are retrieved to perform the process. After “Perform Extraction” is selected, a new dialog will appear asking for the file name where the S2P data should be saved.
As with adapter removal, a few caveats apply
• The two calibration files must have the same frequency lists (i.e., same frequency range and same number of points).
• The cal algorithms and media types may be different but they must both be full 2-Port cals
• The adapter is assumed to be reciprocal (S12 = S21).
NETWORK EXTRACTION Dialog Box - Extract One 2-Port Network - Type A - 2-Port VNAs
