2-Port Transmission Measurement - Agilent Technologies FieldFox N9923A User Manual

6. Attach the shortest cable to the FieldFox PORT 1 connector. This cable is the
7. Press Meas Setup 4 then press Zero.
8. Remove the reference cable from the FieldFox PORT 1 connector.
9. Connect an unterminated, longer cable to the FieldFox PORT 1 connector.
10. Observe the displayed phase difference between the reference cable and the
11. Carefully trim the cable until the phase shift reads zero. The attached
12. Repeat steps 9 through 11 for the remaining cables to be trimmed.
2-Port Transmission Measurements
A 2-Port Transmission measurement is used for measuring electrical length,
insertion loss, gain, or isolation of a DUT at a single CW frequency. The FieldFox
signal source is transmitted out the port 1 connector, through the DUT, and into
the port 2 connector. In the following image, the gain of an amplifier is being
measured.
2-Port Transmission measurement of an amplifier
How to make a 2-Port Transmission Measurement
NOTE In VVM Mode, the power level out of the internal FieldFox source is always
approximately +6 dBm and can NOT be changed. This may be too much input
power to an amplifier.
1. Press Mode then
2. Press Freq/Dist and enter the measurement frequency.
3. Calibrate the FieldFox using one of the methods described on page 70. Before
4. Connect the DUT.
Notes:
 The magnitude value is the gain (positive value) or the loss (negative value) of
 The phase value is the difference in phase (in degrees) between the DUT input
 To measure isolation of the amplifier, reverse the connection to the amplifier
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reference cable. Leave the end of the reference cable open (unterminated).
attached cable.
cable's electrical length is now matched to the reference cable.
VVM
performing a QuickCal or Mechanical Cal, press Meas Setup 4 then
OFF.
the DUT.
and output.
(PORT 1 to the amplifier output).
then
2-Port Transmission.
Zero
N9923A FieldFox User's Guide