Ronde & Schwarz 1304.0004K03, User Manual

Page: 251 / 1071

The Spectrum Application (RF Measurements)
R&S
®
FPL1000
251 User Manual 1178.3370.02 ─ 11
● How to Perform EMI Measurements .....................................................................271
● Measurement Example: Measuring Radio Frequency Interference ......................273
● Optimizing and Troubleshooting EMI Measurements ........................................... 276
6.2.14.1 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 FPL1000 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
FPL1000 performs a final measurement only
on frequencies you have marked with a marker or delta marker. You can assign a dif-
ferent detector to every marker and thus test a particular frequency easily for compli-
ance.
Optionally, you can activate audio demodulation of the signal at the peak marker posi-
tions during the final test (requires the optional additional interfaces R&S
FPL1-B5).
After the final measurement, you can check the signal levels against specified limits.
6.2.14.2 EMI Measurement Results
As the result of an EMI measurement, the measured signal levels and active markers
are displayed in a Spectrum diagram.
Measurements and Results