The term Cal Kit is used to refer to a file that provides the characterized data of the ATE calibration device. These files are stored on the calibration device as ".xkt" files and are required by the PNA calibrations performed using the device. The format of the ".xkt" file is defined by Keysight, ATE calibration devices simply conform. Cal Kits for every calibration device are stored in the non volatile memory of the calibration device along with other files required to perform calibrations. To get a list of the files stored on a calibration devices the following SCPI command must be sent to the device:

SYS:FILE:DIR?

These files are copied from the calibration device to the PNA when a calibration is performed that utilizes that calibration device. The location of these files is defined by the PNA configuration with the key "DirectoryToUse". This directory is used as the root location that will contain each calibration device's files. For example assuming we have:

  • A system that uses 2 FCMs and a PNA-X.
  • The FCMs have the serial numbers 101 and 102.
  • The directory to use is defined as "C:\Temp"


When a calibration is run two folders are created on the PNA-X:

  • C:\Temp\FCM0101
  • C:\Temp\FCM0102


In these folders will be a set of files that match the files stored on the respective device. Included in these files will be the Cal Kits:

  • C:\Temp\FCM0101\P1.xkt
  • C:\Temp\FCM0102\P1.xkt


The calibration library functions ensure that the file stored on the PNA are current and matches the file stored on the calibration device through the use of an MD5 hash. If the MD5 hash on the device differs from that on the PNA then the files on the PNA are replaced. Upon yearly re-characterization the characterization files are updated, with a new MD5 hash triggering automatic update of cal kit files by the calibration library.