Download SSA3030 Spectrum Analyzer User`s Manual - R

SIGLENT
Freq Marker 1
Reference Level -40 dBm
Attenuation 10 dB
445.000000 MHz
-79.99 dBm
Log
10
dB/
RBW
Trac
500Hz
e 20
Dete
ction
Posit
ive
Peak
Center Freq 444 MHz
RBW 500 Hz
Video BW 500 Hz
Span 100 kHz
Sweep Time 560.000 ms (601 dots)
Fig. 3-16 Activate Trace Average to Measure Small Signals
Section 6 Measure Harmonic Distortion
1 Definition of harmonic distortion
Most of transmission devices and signal sources contain harmonics that are often required to be
measured. In fact, the measurement of harmonic distortion is one of the widest applications of
spectrum analyzer. The measuring procedure described hereunder can be employed to rapidly
measure the harmonic distortion. The measuring procedure can measure the correlation between
harmonic amplitude and signal source frequency.
2 Function of spectrum analyzer to be used
For the measurement of harmonic distortion, a group of important operating skills of spectrum
analyzer are presented hereunder, including setting the sweep width by means of start frequency
and stop frequency, setting the video bandwidth, and using two frequency markers for relative
measurement. Meanwhile, the section also demonstrates how to use the frequency markers to set
the signal frequency as the center frequency and set the value of center frequency as the frequency
step.
3 Measuring method of harmonics
There are two common methods to measure the harmonic distortion with spectrum analyzer.
Method A is a quick one and can display the fundamental wave and its harmonics at the same time.
Method B needs a long time of measurement, but it can well measure the harmonic signals close
to the background noise.
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