Keysight N9912A User Manual page 100

Calibration for NA, CAT, and VVM Modes
Why and When to Calibrate
— If a jumper cable or adapter is required to connect the DUT to the FieldFox,
connect those components to the FieldFox RF Out connector NOW. The
effects of those components will be measured and removed during the
calibration, and only the effects of the DUT will be displayed in the
measurement results. These should be high-quality components!
— Do NOT connect anything at the cal reference plane where the DUT
connects.
— Then Press QuickCal.
Optionally Connect Load(s)
— Connect a Load standard at the point where the DUT will be connected and
press
7- 4
Measure under the following conditions:
— When a jumper cable has too much loss. If a 'Cal Failed' error
appears and you skipped the Load measurement, then perform the
Cal again but include measuring the Load.
— When your DUT has high return loss such as the reject band of a
filter. Then measuring the load improves accuracy. Even with the
optional Load, phase accuracy begins to degrade when the return
loss is greater than about 20dB.
Keysight N9912-90001 User's Guide