Rohde & Schwarz R&S FPH, Руководство пользователя

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Spectrum Analyzer Mode
R&S ® Spectrum Rider FPH
127 User Manual 1321.1011.02 ─ 06.00
If the measurement time you have entered was greater than the sweep time, the
R&S Spectrum Rider sets a burst length equal to the sweep time. To work with a
greater burst length, you have to increase the sweep time first.
The minimum burst length is the time corresponding to one trace pixel (= sweep
time / 711).
6.1.4.3 Setting the Reference Level
The reference level is the power level that the R&S Spectrum Rider expects at the RF
input. When selecting the reference level, make sure that you do not overload the R&S
Spectrum Rider by applying a signal whose power exceeds the maximum reference
level.
As the resolution bandwidths of the R&S Spectrum Rider are implemented digitally
after the A/D converter, the signal level at the A/D converter can be higher than the
level indicated by the trace, depending on the selected resolution bandwidth.
To prevent the A/D converter from being overloaded, the signal must be measured at
the widest resolution bandwidth and video bandwidth with the peak detector. The trace
maximum then determines the best reference level.
To simplify operation and to prevent incorrect measurements, the R&S Spectrum Rider
has an automatic routine for setting the reference level.
1. Press the [MEAS] key.
2. Select the "Level Adjust" softkey.
The R&S Spectrum Rider performs a measurement to determine the ideal refer-
ence level.
It uses a resolution bandwidth of 3 MHz, a video bandwidth of 3 MHz and the peak
detector. After finishing the automatic measurement, the R&S Spectrum Rider sets
the ideal reference level.
6.1.4.4 Using a Trigger
When measuring a burst, it is often to set a trigger before measurement is taken.
If a trigger is active, the R&S Spectrum Rider uses the video trigger for TDMA mea-
surements by default. The video trigger level is at 50 % of the range of the vertical axis
but is variable. This means, the R&S Spectrum Rider triggers a measurement if the ris-
ing edge of the burst exceeds this 50 % line.
If the DUT features some sort of trigger equipment, you can also use an external trig-
ger to trigger measurements.
1. Connect the DUT trigger output to the R&S Spectrum Rider trigger input.
2. Press the [SWEEP] key.
3. Select the "Trigger" softkey.
The R&S Spectrum Rider opens a submenu to select the trigger setting.
Performing Spectrum Measurements