Ceyear 4041 Series, Руководство пользователя

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Chapter IV Spectrum Analyzer Mode
38
Press
【
Preset
】
.
Press
【
Freq
】
, [Center Freq], 999.98 [MHz].
Press
【
Span
】
, [Span], 100 [kHz].
Press
【
Ampt
】
, [Ref level], -10 [dBm].
Press
【
Ampt
】
, [Atten Auto Man], 40 [dB].
c) Activate the noise marker.
Press
【
Marker
】
, [Marker Noise Off On].
It should be noted that the current detection mode will be automatically set as the sampling detection. If it is
expected to obtain noise power values under different bandwidths, the value should be corrected by increments of
10×log (BW) according to the current bandwidth. For example, if it is expected to obtain the noise power value
within 1 kHz bandwidth, an increment of 10×log (1,000) or 30 dB should be added to the read data.
d) Reduce the measurement error by increasing the measurement time.
Press
【
Sweep
】
, [Sweep Time Auto Man], 3 [s].
When the average detection is adopted, increasing the sweep time can average the trace data in longer intervals, so
as to reduce the measurement error.
e) Move the marker to 1 GHz.
Press
【
Marker
】
, and rotate the knob on the front panel to set the noise marker reading to 1 GHz.
The noise marker value is obtained based on 5% of the whole scan trace point number. These points center around
the marker position. The noise marker position will not be located at the peak point of signal. Since the signal
peak position does not have enough trace points for calculation, the noise signal will average the trace points
below the signal peaks in case of narrow resolution bandwidth, as shown in Fig 4-11.
Fig 4-11 Noise measurement by using the noise marker function
f) Set the spectrum analyzer to zero span by centering on the marker position.
Press
【
Peak
】
, [Marker Center Frequency].
Press [Span], [Span], [Zero Span].