Rohde & Schwarz FSW26 - Controlling V-Networks (LISN)

Measurements
R&S
®
FSW
295User Manual 1173.9411.02 ─ 19
The resolution bandwidth should cover at least one sweep point (more is better). If this
condition is not met, signals or interferences could be missed during refined measure-
ment of narrowband interferers. If the distance between two sweep points is larger than
RBW/3, a warning is displayed in the status bar ("Increase sweep points").
Example:
Linear axis:
With a linear axis, the distance between the sweep points is equal, e.g. 200 kHz.
Logarithmic axis:
With a logarithmic axis, the distance between sweep points is variable. In the spectrum
from 10 Hz to 100 Hz, the distance is a few Hz. Between 100 MHz and 1 GHz, the dis-
tance is several MHz.
The R&S FSW EMI measurement supports a maximum of 200000 sweep points. This
number is based on typical bands measured with a single resolution bandwidth. There
are sufficient sweep points to make sure that a signal is found during the refined mea-
surement, even when covering 30 MHz to 1 GHz with logarithmic scaling and 120 kHz
RBW.
5.13.3.4 Controlling V-Networks (LISN)
For measurements on power lines, the R&S FSW EMI measurement adds functionality
to control a line impedance stabilization network (LISN) directly. Thus you can deter-
mine the interference caused by power supplies and cables.
You can connect the LISN to the user port of the R&S FSW. Control cables for the vari-
ous LISNs are available as accessories. The R&S FSW then controls which phase of
the LISN is to be tested and outputs the information to the user port.
The R&S FSW EMI measurement supports several V-networks. For each type of net-
work, you can define the phase you want to test for interferences. The R&S FSW EMI
measurement allows you to test one phase at a time.
Electromagnetic Interference (EMI) Measurement (R&S FSW-K54)