Follow the procedure "To Create a New Cal Kit Definition from an Old One" to update the coefficients of Waveguide Standards used in the Cassini CalKit instrument. Waveguides use a Short, Short-Offset and a Load, called SSL vs OSL Open-Short-Load "SMA" standards with a center conductor.

To Create a New Cal Kit Definition from an Old One:

1. From the Cassini application, choose System > Tester to open the Configuration window.
2. Choose Instrument > Add Cal Kit menu and left click on an existing Cal Kit with a Waveguide STD and choose select to activate the previous CalKit definition and add it to the Configuration.
3. Select the CalKit instrument by left clicking and then choose Calibration > Inspect from the right mouse button menu to open the "Inspecting:..." window.
4. Double-click on shortOffset entry to open another "Inspecting:..." window .
5. Select length in the left pane and in the right pane, change the length to be the correct length, in meters, for the short offset.
6. Click on length again and choose yes from the Save dialog box. This temporarily saves the value in memory, and does not permanently save
7. Close that 'Inspecting' panel.
8. Repeat steps 4-6 with the longOffset entry, entering the correct value in meters for the long offset length.
9. In the Configuration window, highlight the CalKit instrument and choose Calibration > Save from the right mouse button menu.
10. Enter a new Cal kit name and choose OK to proceed. Do NOT use the old name, as that would overwrite the Cal Kit definition. (See "Cal Kit Naming Convention" below)
11. Now, in the Configuration window, select the Cal Kit instrument and choose Remove from the right mouse button menu. When it asks if you're sure, choose Yes.
12. Finally, choose Instrument > Add CalKit, find and add the new cal kit that you created and confirm that the lengths are proper.

Background:
When using waveguide standards, an open is not a full reflection because it radiates signal out of the waveguide, typically resulting in a 10 dB to 12 dB return loss. Instead of an open-short, two shorts offset by a precise amount are used. These shorts are 180 degrees apart at one frequency, less than 180 degrees below that frequency, and more than 180 degrees above it. The tester calculates the phase difference from the waveguide dimensions and the offset value. The phase difference must not get too close to 0 or 360 degrees at any frequency to avoid mathematical issues. The offset is usually designed to be 180 degrees at the middle wavelength, not the middle frequency, due to waveguide dispersion.

So the most important specs for the SSL are the precise offset length between the 2 shorts and the precise waveguide 'H' dimension, stored in meters. An H-Bend is bent in the "Hard" direction along the long side.

The offset length must be provided by the Original Equipment Manufacturer (OEM), and different manufacturers supply one of these set of standards:
A) A flush short and an offset shim
B) Flush short and 2 offset shims
C) 2 offset shorts.

Cal Table:

Name	Description (units)	Value
shortOffset	Zero value for flush short or OEM provided length type "C - two offset shorts" (meters)	0.0
longOffset	OEM provided length (close to 0.00135 meters) The difference between the offsets that should be about 0.00135 meters. If there are 2 offsets, then the 'shortOffset' and 'longOffset' should be whatever the manufacturer specifies for those 2 offsets. (meters)	0.00135
dim	waveguide's 'H' dimension in meters (WR12 example) (meters)	0.0030988
sn	serial number that you assign to that component of that cal kit. It can be anything you choose within single quotes ' '	'1/4 lamda short'
z0	Characteristic impedance, it is not really 50 ohms in waveguide but we always leave it at 50 ohms. (ohms)	50.0

Cal Kit Naming Convention:
The RiCalKit Guru object has a Name that includes underscores "_" between the customer site name (RI), the last valid cal date in YYYY-MM-DD notation (2020-01-14), the serial numbers of the SSL Waveguide Standards (WR12-#####). "RI_2020-01-14_WR12-12345" Before calibration, check that today is before the date and the serial numbers match, if not, the Cal Kit object needs to be reviewed.

Figure 1: Example WR12 CalKit