Port Transmission Measurements - Agilent Technologies FieldFox N9913A User Manual

10. Connect an unterminated, longer cable to the FieldFox PORT 1 connector.
11. Observe the displayed phase difference between the reference cable and the
NOTE The VVM phase reading shows a maximum of ±180°. Therefore, the electrical
length of the untrimmed cable MUST be within 180° of the reference cable.
12. Carefully trim the cable until the phase shift reads zero. The attached cable's
13. Repeat steps 10 through 12 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
1. Press Mode then
2. Press Freq/Dist and enter the measurement frequency.
3. Press Meas Setup
4. Calibrate the FieldFox using one of the methods described on page 144.
5. 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
146
untrimmed cable.
electrical length is now matched to the reference cable.
VVM
passive devices. Select Low for amplifiers.
Before performing a QuickCal or Mechanical Cal, press Meas Setup 4 then
Zero OFF.
the DUT.
and output.
(PORT 1 to the amplifier output).
2-Port Transmission.
then
4 then More Output
then
Power. Select High for
FieldFox User's Guide