Rohde & Schwarz FSW13, Руководство пользователя

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Measurements
R&S
®
FSW
120 User Manual 1173.9411.02 ─ 19
The displayed noise level of a signal analyzer depends on its noise figure, the selected
RF attenuation, the selected reference level, the selected resolution and video band-
width and the detector.
For details see:
●
chapter 6.4.1.2, "RF Attenuation" , on page 394
●
chapter 6.4.1.1, "Reference Level" , on page 393
●
chapter 6.5.1.1, "Separating Signals by Selecting an Appropriate Resolution Band-
width"
, on page 403
●
chapter 6.5.1.2, "Smoothing the Trace Using the Video Bandwidth" , on page 404
●
chapter 7.3.1.1, "Mapping Samples to Sweep Points with the Trace Detector" ,
on page 452
This measurement example shows the different factors influencing the S/N ratio.
Table 5-2: Signal generator settings (e.g. R&S SMU)
Frequency 128 MHz
Level -95 dBm
1. Preset the R&S
FSW.
2. Set the center frequency to 128 MHz .
3. Set the span to 100 MHz .
4. Set the reference level to
-30 dBm .
The signal is measured with the auto peak detector and is completely hidden in the
intrinsic noise of the R&S
FSW.
Fig. 5-1: Sine wave signal with low S/N ratio
Basic Measurements