Calibration kit definitions in .ckm files to be loaded with the Cal Kit Manager 2.1

The page describes in some detail how to create .ckm files using the VNA Cal Kit Manager version 2.1 software, and also includes a .ckm file for the Keysight N9910X-800 calibration kit, for which no .ckm file is available from Keysight. That file is saved as N9910X-800.ckm. Kirkby Microwave can create .ckm files for any of our short open load thru (SOLT) calibration kits such as the SMA kit, or the type-N calibration kit. On this page, it is shown how to create a .ckm file for a Keysight N9910X-800 T-calibration Kit. This was created in response to someone seeking help on the HP Agilent Test Equipment Yahoo group to obtain such a file.

The VNA Cal Kit Manager version 2.1 is a Microsoft Windows based application, written by Barry Brown, a former HP employee. It is a 32-bit bit application, we have only run under Windows XP, but would suspect it would work on more modern version of Windows.

The software can:

  1. Write a vector network analyzer (VNA) disk files for some VNAs, including the 8753, as well as the 8719, 8720, 8722 series instruments, and 8510 series VNAs. This method requires you have a floppy disk, so is not suitable for old vector network analyzers including the 8753A, 8753B, 8753C, 8719A, 8719B, 8719C, 8720A, 8720B, 8720C, 8722A, 8722B or 8722C. Note the early 8510A and 8510B do not have floppy disk drives, but tape drives. However, the floppy disk files are suitable for the D, E, ES and ET versions of these VNAs.
  2. Read/write a file with the extension .ckm to copy data on calibration kits to/from early HP/Agilent VNAs.
  3. Send the contents of a user-defined calibration kit to the VNA over GPIB, which is also known as IEEE-488 and HPIB.
  4. Retrieve the contents of a calibration kit from the VNA over GPIB

To define a calibration kit totally from the beginning would be very tedious and require a lot of knowledge. It is far better to modify one of the calibration kit definitions included with the VNA Cal Kit Manager software. It is suggested that the following procedure be used to select a suitable kit to start modifying:

If the above recommendations are followed, there should be no need to modify the class asignments, which are the most complicated parameters to set up.

Kirkby Microwave vector network analyzer (VNA) calibration kits.

Kirkby Microwave supply individually measured coefficients with each kit. Since Kirkby Microwave can't generate this proprietary binary format automatically, and each calibration kit sold would need a different .ckm file, the .ckm files are not routinely supplied, but we can generate them for customers that want them by using the Cal Kit Manager 2.1 software. This page describes how customers can do it themselves, but we are always happy to do this. The .ckm file can be loaded into the Cal Kit Manager 2.1 software, which then allows one to copy the coefficients to the VNA via GPIB, and if your VNA supports it, via a floppy disk.

Keysight calibration kits.

There exists a large number of Keysight calibration kits. The definition of the standards can be found at Keysight Calibration Kit Definitions page. These are never available in the format use by the VNA Cal Kit Manager version 2.1 but in formats readable by some HP, Agilent or Keysight VNAs. Generally the newest kits don't have files for the older obsolete instruments.

Keysight N9910X/801 Type N Calibration Device - a T-shaped kit designed for portable use.

The definitions of this fairly recent kit are only given in a N9910X-800.xkt file for reading by an Agilent/Keysight FieldFox portable instruments, although a modern ENA, PNA and any PNA-X can read the .xkt file. Fortunately the .xkt file format is easy to read by a human, as its basically an XML file, so can be viewed with a text editor. Looking at the file were can see a number of parameters, including the following for the open calibration standard:

<C0>-2.686E-15</C0>
<C1>-7.919E-25</C1>
<C2>6.079E-34</C2>
<C3>-6.548E-44</C3>
<OffsetDelay>7.097E-11</OffsetDelay>
<OffsetLoss>2134000000</OffsetLoss>
<MaximumFrequencyHz>6000000000</MaximumFrequencyHz>

It should be note that the numbers above should not be entered directly into the VNA Cal Kit Manager software, but need to be changed to the format the software requires, which are as shown in the image below:

With the above taken care of, the same rules applied to the short, and the fact for an 8753 which this was designed for, the coefficients L0, L1, L2 and L3 can't be set, the data should be entered in to the Cal Kit Manager 2.1 software as shown below:

VNA Cal Kit Manager software

The Cal Kit Properties tab should be modified, with a suitable name for the kit.

The data should then be saved to the file with a suitable name such as N9910X-800.ckm. The coefficients should then be sent to the VNA using the item Send Kit to VNA, on the GPIB menu. A National Instruments, HP or Agilent GPIB board will be needed.