General Description
R&S
®
CMW-B400B/-B405A
22
User Manual 1176.8116.02 ─ 04
Fig. 3-11: FFT noise diagram
The result diagram displays the measured audio level vs. the frequency.
The measurement uses a Fast Fourier Transformation (FFT) compatible to the gener-
ated noise signal. That means, the used sampling rate and the FFT size yield a fre-
quency resolution matching the frequency spacing of the generated test tones.
Example: With a sampling rate of 48 kHz and an FFT size of 4096, the resulting fre-
quency resolution equals 48000 / 4096 = 11.71875 Hz. So this frequency spacing
would be used for the generated test signal.
This combination of matching noise signal and FFT allows to analyze the frequency
response of a DUT in a single measurement.
3.4.4 Modifying Diagrams
To change the appearance and contents of a diagram, press the "Diagram..." softkey.
Then use the following hotkeys at the bottom of the GUI. Depending on the diagram,
not all hotkeys are available.
Hotkey
Description
"Trace ..."
Select the trace types to be displayed in the view.
"X Scale... / Y Scale..."
Modify the ranges of the X-axis and the Y-axis.
"View Diagr. / Table"
Switch between diagram and table presentation.
To enlarge/reduce a diagram, double-click it or select the diagram and press ENTER
or the rotary knob.
3.4.5 Using Markers
To access the markers of a diagram, press the "Diagram..." softkey. Then use the fol-
lowing hotkeys at the bottom of the GUI to activate markers and to modify their posi-
tion. Depending on the diagram, not all hotkeys are available.
Measurement Results
深圳德标仪器
135-1095-0799
