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 6-19 while performing the steps in this procedure. Also refer to
page 6-41 for an explanation of A1, A2, and A3.
2. Perform a 1-port calibration at “Reference Port 1”. Refer to Step A of Figure 6-19.
Figure 6-19 Determining the Electrical Delay Setup
3. Connect the A3 adapter to “Reference Port 1” as shown in Step B of Figure 6-19.
Connect a short to the open end of the A3 adapter.
4. Measure the delay of the adapter by pressing .
5. Divide the resulting delay measurement by 2 to determine the del a y of the thru and the
short in one direction.
6. Determine the offset delay of the calibration short by examining the define standard
menu (see "Define Standard Menus" on page 7-59).
7. Subtract the offset delay of the short (determined in step 6) from the delay of the thru
and the short in one direction (determined in step 5). The result is electrical delay of the
thru. This value is used in the next step.
8. Modify the calibration kit thru definition by entering in the electrical delay of adapter
A3. Save this as a user kit.
For example, if A3 has 100 ps of delay, press:
Format
DELAY
Cal
CAL KIT
MODIFY
DEFINE STANDARD
4x1
MODIFY STD DEFINITION
SPECIFY OFFSET
OFFSET DELAY
0.100 G/n
STD DONE (DEFINED)
KIT DONE (MODIFIED)
SAVE USER KIT