Ceyear 4041 Series, User Manual

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Chapter IV Spectrum Analyzer Mode
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spectrum analyzer is shown in Fig 4-9.
Fig 4-9 Observing the drift signal by use of maximum hold function
4.1.6 Measurement of noise signal
1) Definition of noise signal
In the communication system, the noise amplitude is often presented by the signal to noise ratio. The greater the
noise level added in the system is, the poorer the signal to noise ratio is, and the more difficult it is to demodulate
the modulation signal. In the communication system, the signal to noise ratio measurement often means the carrier
to noise ratio measurement.
The contents below describe how the marker function of the 4041 series spectrum analyzer is used to measure the
signal to noise ratio, and noise. The instance describes the signal to noise ratio measurement of signal (carrier) of a
single frequency point. If modulation signals are contained in the detected system, this test process should be
modified to alter the level of modulation signal.
2) Measurement of the signal to noise ratio
a) Set the signal generator output signal:
Set the signal generator frequency at 1 GHz and signal power at -10 dBm, connect the signal generator output to
the input port of spectrum analyzer, as shown in Fig 4-1, and turn on the RF switch.
b) Set the center frequency, span, reference level and attenuator.
Press
【
Preset
】
.
Press
【
Freq
】
, [Center Freq] and 1 [GHz] successively.
Press
【
Span
】
, [Span] and 5 [MHz].
Press
【
Ampt
】
, [Ref Level], -10 [dBm].
Press
【
Ampt
】
, [Atten Auto Man], 40 [dB].