R&S FSQ Signal Analyzer - Rohde & Schwarz

R&S FSQ Getting Started
Measurements on Modulated Signals
2.5.1.2 Measurement Example 2 – Measuring the Modulation Depth of an AM Carrier
in the Frequency Domain
Test setup
Settings on the signal generator (e.g. R&S SMIQ)
Frequency: 100 MHz
Level: -30 dBm
Modulation: 50 % AM, 1 kHz AF
Measurement with the R&S FSQ
1. Set the R&S FSQ to the analyzer mode
➢ Press the SPECTRUM key.
The R&S FSQ is in the analyzer mode.
2. Set the center frequency to 100 MHz and the span to 0 kHz
➢ Press the FREQ key and enter 100 MHz.
➢ Press the SPAN key and enter 5 kHz.
3. Activate the marker function for AM depth measurement
➢ Press the MEAS key.
➢ Press the MODULATION DEPTH softkey.
The R&S FSQ automatically positions a marker on the carrier signal in the
middle of the graph and one delta marker on each of the lower and upper AM
sidebands. The R&S FSQ calculates the AM modulation depth from the ratios
of the delta marker levels to the main marker level and outputs the numerical
value in the marker info field
Operating Manual 1313.9681.12 - 01 2.29