2-Port Insertion Loss Measurements - Agilent Technologies N9913A User Manual

The displayed trace shows the Cable Loss values in one direction through the
cable. A Return Loss measurement would show the loss for both down the cable
and back. Therefore, a Cable Loss measurement is the same as a Return Loss
measurement divided by 2.
The average Cable Loss across the specified frequency range is shown on the
screen below the graticules.

2-Port Insertion Loss Measurements

A 2-port Insertion Loss measurement is used to measure the loss through a DUT
(device under test) – or cable – over a specified frequency range. The FieldFox
signal source is transmitted out the RF OUT connector, through the DUT, and
into the RF IN connector. Both ends of the DUT must be connected to the
FieldFox, either directly or indirectly using the cable used in the normalization
cal.
'Insertion' loss simply means loss through a device, usually expressed in dB. It is
exactly the same measurement as "S21 Transmission" in NA Mode.
2-port Insertion Loss measurements are generally more accurate than 1-port
Cable Loss measurements.
How to make a 2-port Insertion Loss Measurement
1. Press Mode then CAT.
2. Then then .
More Insertion Loss (2-Port)
3. Press Freq/Dist and enter and frequency values of the
Start Stop
measurement.
4. Press Sweep 3, then select a Resolution setting.
5. Press Cal 5, then perform a calibration. Learn more on page 70.
6. Connect the DUT and view the insertion loss measurement results.
When measuring very long lengths of cable, it may be necessary to increase the
sweep time. Learn how on page 25. Learn why in the Supplemental Online
Help: http://na.tm.agilent.com/fieldfox/help/FieldFox.htm
CAT (Cable and Antenna Test) Mode 29