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R&S FSH
Spectrum Analyzer Mode
Performing Spectrum Measurements
Operating Manual 1173.6275.12 - 30
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3.1.7 Measuring the Harmonic Distortion
The Harmonic Distortion measurement is an easy way to identify the harmonics of a
DUT. In addition to the graphic display of the harmonics, this measurement mode also
calculates the Total Harmonic Distortion (THD) and shows the results.
You can perform a Harmonic Distortion measurement in frequency sweep (span > 0)
and zero span mode (span = 0). When starting the measurement, the R&S FSH looks
for the first harmonic of the signal (= the highest signal) in the defined frequency range.
It then adjusts the frequency axis so that all harmonics are visible. In zero span mode,
the center frequency remains the same.
► Press the MEAS key.
► Press the "Meas Mode" softkey.
► Select the "Harmonic Distortion" menu item.
The R&S FSH starts to measure the harmonic distortion.
The search for harmonics starts as soon as you enter the Harmonic Distortion
measurement. Upon entering the measurement, the R&S FSH automatically adjusts
the settings in order to display the selected number of harmonics (default = 2) on the
screen.
Screen layout for the harmonic distortion measurement
1
Harmonics list
2
Total harmonic distortion in %
3
Total harmonic distortion in dB
4
Trace
5
Markers indicating harmonics (blue lines)
6
Harmonic distortion softkey menu