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Concepts and Features
R&S
®
ZNB/ZNBT
215
User Manual 1173.9163.02 ─ 53
The Automatic Harmonic Grid from the option R&S
ZNB/ZNBT-K2 "Time domain
Analysis" is used to ease setting up the frequency grid for all measurements provided
by the option R&S
ZNB/ZNBT-K20.
5.7.3
Distance to Fault Measurements
Option R&S
ZNB-K3 / R&S
ZNBT-K3
With option K3 "Distance-to-Fault", the R&S
ZNB/ZNBT can locate faults and disconti-
nuities on cables and transmission lines.
Faults produce peaks on the impulse response (in the time domain) that is calculated
from the measured reflection S-parameter trace via inverse Fourier transformation. The
distance between the reference plane and the fault can then be calculated from the
propagation time, accounting for the electrical properties of the transmission line.
Moreover it is possible to define which of the peaks shall be considered as being due
to a fault.
The following example shows the reflection at the end of a faultless open cable con-
nected to test port 2. A full one-port calibration ensures that the distance is measured
from the test port position (reference plane = distance zero). The horizontal position of
marker "M2" corresponds to the cable length of 1417
mm, the additional peak at posi-
tion "M1" is due to a bad connection between the cable and the test port.
Optional Extensions and Accessories