Cable and Antenna Test Mode
R&S
®
ZNH
115
User Manual 1334.5985.02 ─ 02
7.1.3
1-Port Cable Loss Measurement
(Short + Open) / 2 measurement format
When the "(Short + Open) / 2" format is selected, additional calibration steps are
required to terminate the end of the cable under test with a short and open before the
cable loss measurement is performed.
The cable loss measurement evaluates the power attenuation of a cable over a speci-
fied frequency range in dB. The amount of power that gets absorbed depends on the
frequency and length of the cable.
The 1-port cable loss measurement can be performed in the following measurement
formats:
●
Normal
●
(Short + Open) / 2
1. Press [MEAS] key.
2. Select "Cable Loss" softkey.
The R&S
ZNH displays a submenu to select measurement format.
3. Select "Normal" or "(Short + Open) / 2" menu item.
The R&S
ZNH evaluates the cable loss over its entire frequency (span) in dB.
The numerical result is the average cable loss over the specified span.
shows the typical results of a cable loss measurement with a steadily declining loss
over the selected frequency range and several maximums and minimums.
By default, the R&S
ZNH evaluates the cable loss over its entire frequency range (full
span of the R&S
ZNH). When you reduce the span, make sure to define a span that is
appropriate for the measurement, especially for high center frequencies, and consider
the cable length and the wavelength of the selected center frequency. For a typical
cable loss trace, you should select a span that is large enough to evaluate at least one
peak and one minimum. Otherwise, the result might not be valid.
If the cable loss is constant over a large span (for example in case of low center fre-
quencies), you can select any span.
However, if the cable loss is greater than 20 dB, you are better off using the (
) measurement, because the cable loss measurement might yield invalid results.
Performing Cable and Antenna Measurements
