Measurements
R&S
®
FSW
297
User Manual 1173.9411.02 ─ 19
R&S
FSW looks for the strongest peaks in the frequency range you are measuring and
positions a marker on those peaks after each sweep. If a
limit line
is assigned to the
trace, the peak search is based on the level difference between the trace and the limit
line. For each active marker a peak is searched. You can use up to 16 markers simul-
taneously.
The largest peak is always assigned to the active marker with the lowest number; sub-
sequent peaks are assigned to the active markers in ascending order.
The R&S
FSW allows you to distribute markers among several traces. If you do so, the
marker with the lowest number assigned to a particular trace is positioned on the larg-
est peak of the corresponding trace.
Manual peak search
If automatic peak search is off, you can set the markers to any frequency you need
more information about manually. You can change the marker position with the rotary
knob or the cursor keys, or position it to a particular frequency with the number keys.
Setting markers is the same as setting markers in other Spectrum measurements. For
more information see
Searching for peaks over several traces
You can search for peaks on six traces simultaneously with a different weighting detec-
tor for each trace.
In this case, the R&S
FSW searches for peaks on all traces separately, provided that
you have assigned at least one marker to each trace.
A typical selection for EMI measurement is to use the peak and the average detector.
After initial measurement, search for peaks on the peak trace and the average trace
separately so that the distribution of narrowband and wideband sources of interference
can be taken into account.
Example:
●
In the initial measurement, determine the peak on one trace using the average
detector by assigning a marker to that trace. For the marker frequency, perform a
refined measurement using the CISPR or RMS average detector.
●
In the initial measurement, determine the peak on another trace using the peak
detector by assigning another marker to that trace. For this marker frequency, per-
form a refined measurement using the quasipeak detector.
5.13.3.7
Final Measurement at the Marker Position
Finding peaks with the help of an initial marker peak search reduces data to be evalu-
ated and thus measurement time. A final measurement with a special EMI detector can
then refine the intial results.
The R&S
FSW EMI measurement performs the final measurement automatically as
soon as a detector for the final test is defined for an EMI marker and the marker is acti-
vated. The final measurement starts immediately after the marker has been set. The
Electromagnetic Interference (EMI) Measurement (R&S
FSW-K54)
