The procedure for requesting AWR support has changed. Please read all about the new AWR product support process.
Page tree

Versions Compared


  • This line was added.
  • This line was removed.
  • Formatting was changed.


How do I repair a Touchstone S Data file that causes problems when being imported?


Please try this script first: Importing S-Parameter Data . The utility described here is a program that you will need to download and run.  Your company may have strict rules that will not allow that.


  1. Redundant Data Added: Additional information can be added to the file. This includes derived terms such as the Common Mode Rejection Ratio (CMRR). Some VNAs can add this derived data to the file on export. Beware all derived data can be calculated from the s-data anyway, so the addition of such information is only for the benefit of the VNA when the data is re-imported to VNAs that support this capability, and not the end user!

  2. "CR" and "LF" characters: Some VNAs provide UNIX standard text files. These are difficult to read using Notepad when the user wishes to inspect the data for other defects.

  3. Wrong data format: The data set should conform to the pattern defined in the Touchstone documentation. The multi-port multi-frequency data has a fixed standard layout. Please refer to the Touchstone documentation for a definitive description of the S-Data standard.

  4. No specification: There should be a line that specifies impedance level, frequency units (Hz, MHz, GHz etc) and data style (mag/angle - real/imaginary ). If this is not set up correctly in the data file, you will get error message No frequency range defined in the Status window. A typical specification line looks similar to the following:

    # MHZ S MA R 50

  5. Illegal format of text lines: Only three formats are allowed with the lines of text. The acceptable formats are Pure Data, Comment, and Data specification.

    Pure data: first significant character in the line of text has to be a number

    Comment: first significant character "!"

    Data specification: first significant character "#"