User`s guide

6-46
Calibrating for Increased Measurement Accuracy
Calibrating for Noninsertable Devices
Modify the Cal Kit Thru Definition
With this method, it is only necessary to use a thru adapter. The calibration kit thru
definition is modified to compensate for the adapter and then saved as a user kit. However,
the electrical delay of the adapter must first be found. The adapter match will degrade the
effective load match terms on both ports as well as degrade the transmission frequency
response (tracking).
1. Refer to Figure 6-18 while performing the steps in this procedure. (Also refer to
page 6-40 for an explanation of A1 and A2.)
2. Perform a 1-port calibration at “Reference Port 1.”
3. Connect the THRU adapter to “Reference Port 1” as shown in Step A of Figure 6-18.
Figure 6-18 Modifying the Cal Kit Thru Definition Setup
4. Add a short to the open end of the THRU.
5. Measure the delay of the adapter by pressing .
6. Divide the resulting delay measurement by 2.
7. Determine the offset delay of the calibration short by examining the define standard
menu (see "Define Standard Menus" on page 7-58).
8. Subtract the short offset delay from the value calculated in step 5. This corresponds to
the delay of the THRU.
9. Modify the calibration kit thru definition by entering in the electrical delay of the
THRU. Save this as a user kit.
For example, if the THRU has 100 ps of delay, press:
Format
DELAY
Cal
CAL KIT
MODIFY
DEFINE STANDARD
4 x1
MODIFY STD DEFINITION
SPECIFY OFFSET
OFFSET DELAY
0.100 G/n
STD DONE (DEFINED)
RETURN
KIT DONE (MODIFIED)
SAVE USER KIT