Rohde & Schwarz FSV3000, User Manual

Page: 324 / 1489

Measurements and results
R&S
®
FSVA3000/ R&S
®
FSV3000
324 User Manual 1178.8520.02 ─ 08
●
Marker demodulation
(Requires R&S
FSV3-B3)
●
Measurement bandwidths and detectors for EMI measurements
●
Logarithmic scaling of the frequency axis
●
Additional predefined limit lines for EMC standards
●
Predefined transducer factors
●
Additional amplitude units, normalized to 1 MHz
●
LISN control
(Requires R&S
FSV3-B5)
● About the EMI measurement ................................................................................ 324
● EMI measurement results ..................................................................................... 325
● EMI measurement basics ......................................................................................326
● EMI measurement configuration ........................................................................... 335
● EMI result analysis ................................................................................................344
● How to perform EMI measurements ..................................................................... 345
● Measurement example: measuring radio frequency interference .........................347
● Optimizing and troubleshooting EMI measurements ............................................ 349
5.13.1 About the EMI measurement
EMI measurements can be very time-consuming, especially if weighting detectors are
required for the measurement. In addition, EMC testing often requires various proce-
dures to locate local EMI maxima. Such procedures are, for example, movements of
an absorbing clamp, variations in the height of the test antenna or the rotation of the
DUT.
Covering all test setups with one of the (slow) EMI weighting detectors over the
required frequency range can lead to very long measurement times.
Splitting the measurement procedure into several stages, however, can eliminate this
problem.
The first stage is a peak search, used to get a rough idea about the location of peak
levels that can indicate interference over the required frequency range. This stage
uses a detector that allows for a fast sweep time, e.g. the peak detector.
During the second stage, or final test, the R&S FSV/A performs the actual EMC test, a
refined measurement with detectors designed for and required by EMC standards. To
keep measurement times brief, the R&S
FSV/A performs a final measurement only on
frequencies you have marked with a marker or delta marker. You can assign a different
detector to every marker and thus test a particular frequency easily for compliance.
Optionally, you can activate continuous demodulation of the signal during the initial
measurement and at the peak marker positions during the final test.
After the final measurement, you can check the signal levels against specified limits.
Electromagnetic interference (EMI) measurement