Measurements and Results
R&S
®
FSVA3000/ R&S
®
FSV3000
304
User Manual 1178.8520.02 ─ 01
7.12.4
Optimizing and Troubleshooting the Measurement
If the results do not meet your expectations, try the following methods to optimize the
measurement:
●
Set the center frequency to the frequency of the device under test.
●
Adjust the span so the peaks to the left and right of the carrier, produced by the AM
modulated signal, are clearly visible.
If the span is too wide, these signals may fall together with the carrier and the mea-
surement can not be performed.
If the span is too narrow, theses signals are outside of the measured span and the
delta markers can not find these peaks.
The rule of thumb is to set the span to three times the value of the AM modulation
frequency.
7.12.5
How to Determine the AM Modulation Depth
The following step-by-step instructions demonstrate how to determine the AM modula-
tion depth.
For remote operation, see
Chapter 14.5.12.2, "Example: Measuring the AM Modulation
1. Apply a modulated carrier signal to the R&S
FSV/A input.
2. On the R&S
FSV/A, press the [MEAS] key.
3. Select the "AM Modulation Depth" measurement function from the "Select Mea-
surement" dialog box.
The calculated AM Modulation Depth is indicated in the marker information. The
markers required for calculation are displayed in the marker table.
4. If the signal changes significantly during or after the AM Modulation Depth mea-
surement, use the "Search Signals" function to start a new peak search automati-
cally and restart the calculation of the AM Modulation Depth.
AM Modulation Depth Measurement