Verifying Calibration And Jumper Cable Integrity; Compatible Mode Calibrations; Compatible 1-Port And 2-Port Calibrations; Save A Calibration - Keysight N9912A User Manual

Cal ON ? – Questionable Accuracy
If a change made by the user to the output power setting, or a change made
automatically by the FieldFox firmware makes accurate calibration interpolation
questionable, a question mark is added to the screen annotation for all calibration
states (Ex:
the setting has changed. For optimum accuracy, recalibrate using the new settings.

Compatible Mode Calibrations

Because CAT, NA, and VVM modes are very similar, a 1-port or 2-port calibration
that is performed in one mode is automatically applied in the other modes. This
occurs ONLY when modes have the same frequency data points, have the same
Power Level, and have the same IF BW. CAT Mode IF BW is 30 kHz and is NOT
selectable.

Compatible 1-port and 2-port Calibrations

Typically, a 1-port calibration and a 2-port normalization can NOT be maintained at
the same time. The most recently performed calibration will usually overwrite the
other.
 In CAT mode, the 1-port measurement is Return Loss or DTF, and the 2-port
 In NA mode, the 1-port measurement is S11, and the 2-port measurement is S21.
However, a 1-port calibration CAN coexist with a 2-port normalization ONLY when
BOTH of the following conditions occur:
1. A 1-port Cal already exists, then a Normalization Cal is performed. They can NOT
2. The Frequency Range, Resolution, Power (Hi/Low), and IF BW (in NA Mode)
When both conditions occur, you can switch between the 1-port and the 2-port
measurements, and both will remain fully calibrated.
In a DTF measurement, the frequency range over which the calibration is made can
be viewed using the calculated Start and Stop Frequency on the Settings page.
Learn how to see this on page 36.
Save the Calibration
After performing any type of calibration, you can save the FieldFox settings along
with the calibration into a STATE (*.sta) file. These settings and calibration can then
be recalled as necessary. Learn how on page 162.

Verifying Calibration and Jumper Cable Integrity

After calibrating, it is important to verify that the calibration is good. When using a
jumper cable, also verify that the cable is of high quality.
Verify a Calibration
 Connect a LOAD standard at the calibration reference plane (where calibration
 In CAT Mode, select a Return Loss measurement.
 In NA Mode, select a S11 Reflection with Log Mag format.
Calibration for CAT, NA, and VVM Modes
?). The resulting measurement accuracy depends on how much
Cal ON
measurement is Insertion Loss.
be performed in the reverse order.
settings of the two calibrations are identical.
standards were connected). This may be at the end of the jumper cable or at
FieldFox RF OUT connector.
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