Keysight N9912A - 2-Port Insertion Loss Measurements

3- 14 Keysight N9912-90001 User’s Guide
CAT (Cable and Antenna Test) Mode
2-Port Insertion Loss Measurements
3-
13.Press Data Math then Data – Mem. The ripple in the measurement is
removed. These minor imperfections in the cable should not be considered
in the Cable Loss measurement.
14.Use Averaging to remove random noise from high-loss measurements.
Press BW 2
then Average.
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, available with option 110, 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.
For highest accuracy, when measuring the DUT also attach any cable or
adapter that was used in the normalization cal.
How to make a 2-port Insertion Loss Measurement
—Press Mode
then CAT.
—Then More
then Insertion Loss (2-Port).
—Press Freq/Dist
and enter Start and Stop frequency values of the
measurement.
—Press Sweep 3
, then select a Resolution setting.
—Press Cal 5
, then press Normalization. Learn more in “Normalize” on
page 7-6.
— Connect the DUT and view the insertion loss measurement results.
A Normalization Cal is REQUIRED for making accurate 2-port CAT or NA
measurements. Learn “Normalize” on page 7-6
.