Quick Start
R&S
®
ESR
104
User Manual 1175.7068.02 ─ 12
Table 3-6: Signal generator settings (e.g. R&S SMU)
Frequency
128 MHz
Level
-30 dBm
Modulation
50 % AM, 10 kHz AF
1. Set the signal analyzer to the default state by pressing the [PRESET] key.
The R&S
ESR is set to its default state.
2. Select "Spectrum" mode.
3. Set the center frequency to 128 MHz and span to 50 kHz.
a) Press the [FREQ] key and enter
128 MHz
.
b) Press the [SPAN] key and enter
50 kHz
.
4. Activate the marker function for measuring the AM modulation depth.
a) Press the [MEAS] key.
b) Press the "More" key.
c) Press the "AM Mod Depth" softkey.
The R&S
ESR automatically sets a marker to the carrier signal in the center of
the diagram and one delta marker each to the upper and lower AM sidebands.
The R&S
ESR calculates the AM modulation depth from the level differences of
the delta markers to the main marker and outputs the numeric value in the
marker field.
Figure 3-14: Measurement of the AM modulation depth
The modulation depth is displayed as "MDepth". The frequency of the AF signal can be
obtained from the frequency display of the delta marker.
3.5.3.3
Measuring AM-Modulated Signals
The signal analyzer rectifies the RF input signal and displays it as a magnitude spec-
trum. The rectification also demodulates AM-modulated signals. The AF voltage can be
displayed in zero span if the modulation sidebands fall within the resolution bandwidth.
Displaying the AF of an AM-modulated signal (Zero Span)
Test setup
Basic Measurement Examples
