Keysight N9912A - 1-Port Cable Trimming Measurements; How to Make a 1-Port Cable Trimming Measurement

Keysight N9912-90001 User’s Guide 14- 9
VVM (Vector Voltmeter) Mode - Option 308
1-Port Cable Trimming Measurements
1-Port Cable Trimming Measurements
A 1-Port Cable Trimming measurement is used in a cable fabrication procedure
to validate proper electrical length.
How to make a 1-Port Cable Trimming Measurement
1. Press Mode then VVM then 1-Port Cable Trimming.
2. Press Freq/Dist
then enter the frequency for the VVM measurement.
3. Press Meas Setup 4
then Zero OFF.
4. If using an adapter or jumper cable to connect the cables to the FieldFox,
press Cal 5
then select Calibation Type, then either QuickCal (+ Load) or
OSL Cal
. Follow the FieldFox calibration prompts. Learn more about VVM
calibration on page 14-8.
Verification: Perform the following optional steps to ensure that the FieldFox is
properly calibrated. Steps 1 through 9 need only be done once to determine
the difference in phase between the Open and Short standard. Once that value
is known, perform steps 10 through 14 to verify a calibration.
1. Press Mode
then NA. Select S11.
2. Press Freq/Dist
and enter start and stop frequencies that span about 40%
of the VMM measurement frequency. For example, for a 1 GHz
measurement, enter Start .8 GHz and Stop 1.2 GHz.
3. Perform a calibration using a cal kit (NOT Quick Cal).
4. Press Meas 1
then Format Phase.
5. Connect the Short standard to the RF OUT calibration plane.8
6. Press Trace 6
then Math and Memory. Then Data-> Mem.
7. Connect the Open standard to the RF OUT calibration plane.
8. Press Data Math
then Data/Mem.
— The R receiver measures incident
signal (green line) out of the source.
— The A receiver measures reflected
signal (red line) from the end of the
DUT (black line).
— In VVM mode, the display ALWAYS
shows ratioed (A/R) measurements
which is the electrical length of the
DUT.