HP HP 8712ET, User Manual, Page: 231 / 480

ET User’s Guide 6-5
Calibrating for Increased Measurement Accuracy
Measurement Calibration Overview
The Calibration Reference Plane
Most often you will not be connecting your DUT directly to the
analyzer's front panel. More likely, you will be connecting your DUT to
some sort of test fixture or cable(s) that is connected to the analyzer. See
Figure 6-3, “The Calibration Reference Plane.” The calibration reference
plane is where you connect your calibration standards, and the
measurement reference plane is where you connect your DUT. Best
measurement results occur when these reference planes are aligned so
that you calibrate out the effects of the test fixture and its associated
cables and hardware.
Figure 6-3 illustrates that one method of aligning
the reference planes is to connect your calibration standards at the same
point that you connect your DUT. For information on selecting
calibration standards, refer to
“Calibration Kits” on page 6-16 . A less
accurate method is to connect the calibration standards to the analyzer’s
ports and then use the port extensions feature, previously explained in
Chapter 5 .
Figure 6-3 The Calibration Reference Plane