The Spectrum Application (RF Measurements)
R&S
®
FPL1000
474
User Manual 1178.3370.02 ─ 03
Frames are sorted in chronological order, beginning with the most recently recorded
frame at the top of the diagram (frame number 0). With the next sweep, the previous
frame is moved further down in the diagram, until the maximum number of captured
frames is reached. The display is updated continuously during the measurement, and
the measured trace data is stored. Spectrogram displays are continued even after sin-
gle measurements unless they are cleared manually.
The maximum number of frames that you can capture is summarized in
.
Table 7-23: Correlation between number of sweep points and number of frames stored in the history
buffer
Sweep Points
Max. History Depth
≤
1250
20000
2001
12488
4001
6247
8.001
3124
16.001
1562
32.001
781
The scaling of the time axis (y-axis) is not configurable. However, you can enlarge the
spectrogram display by maximizing the window using the "Split/Maximize" key.
Frame analysis - Frame count vs. sweep count
As described for standard spectrum sweeps, the sweep count defines how many
sweeps are analyzed to create a single trace. Thus, for a trace in "Average" mode, for
example, a sweep count of 10 means that 10 sweeps are averaged to create a single
trace, or frame.
The frame count, on the other hand, determines how many frames are plotted during a
single sweep measurement (as opposed to a continuous sweep). For a frame count of
2, for example, 2 frames will be plotted during each single sweep. For continuous
sweep mode, the frame count is irrelevant; one frame is plotted per sweep until the
measurement is stopped.
If you combine the two settings, 20 sweeps will be performed for each single sweep
measurement. The first 10 will be averaged to create the first frame, the next 10 will be
averaged to create the second frame.
As you can see, increasing the sweep count increases the accuracy of the individual
traces, while increasing the frame count increases the number of traces in the diagram.
Especially for "Average" or "Min Hold" and "Max Hold" trace modes, the number of
sweeps that are analyzed to create a single trace has an effect on the accuracy of the
results. Thus, you can also define whether the results from frames in previous traces
are considered in the analysis for each new trace ( "Continue Frame" ).
Trace Configuration
