Please accept this note as a rant and I am bloody PO. I am using AFR on the PXI network analyzer. AFR works great but has a major, major flaw (Keysight will call it a feature).
We have AFR only on one VNA. This was done because besides measuring data AFR can also read s-parameter files. So we take data on a 50 GHz VNA save the S-parameter file (filename.S2P) and generate the modelsfor the two ports. Been working great for 1 year.
Well today I get this error.
A S2P has no port identifier though the order is S11. S21, S12, S22 in the generic sense. I did track this down to the following. Inside the file Keysight adds comments when storing the file off the VNA and here is what was in it.
!Date: Thursday, December 06, 2018 20:02:24
!Correction: S33(Full 2 Port(3,4))
!S43(Full 2 Port(3,4))
!S34(Full 2 Port(3,4))
!S44(Full 2 Port(3,4))
!S2P File: Measurements: S33, S43, S34, S44:
# Hz S dB R 50
Bloody hell. Since when does adding comments to SxP files DICTATE how the file is used? And no this are not Version 2 SxP files and yes I have been around since EEsof first generated this file format in the early 1980's
Needless to say once I changed all the files to say port 1 and 2 (via text editor) like
!Correction: S11(Full 2 Port(1,2))
!S21(Full 2 Port(1,2))
!S12(Full 2 Port(1,2))
!S22(Full 2 Port(1,2))
!S2P File: Measurements: S11, S21, S12, S22:
# Hz S dB R 50
everything worked as it should be.
PLEASE CORRECT THIS.
Thanks for letting me rant.
Michael J. Virostko
Principal Product Application Engineer
+1 978.577.6347 direct