Measuring The Modulation Index Of An Am Signal - Keysight X Series Measurement Manual

Demodulating AM Signals

Measuring the Modulation Index of an AM Signal

Measuring the Modulation Index of an AM Signal
This procedure demonstrates how to use the signal analyzer as a fixed-tuned
(time-domain) receiver to measure the modulation index as a percent AM value of an
AM signal.
Step
1 Set up the signal source.
2 Connect an Keysight
ESG RF signal source to
the analyzer RF INPUT
as shown.
3 Select the mode.
4 Preset the analyzer.
5 Set the center frequency,
span, RBW and the
sweep time.
Action
a. Set the source frequency to
300 MHz.
b. Set the source amplitudes to
−10 dBm.
c. Set the AM depth to 80%.
d. Set the AM rate to 1 kHz.
e. Turn AM on.
• Press Mode, Spectrum
Analyzer.
• Press Mode Preset.
a. Press FREQ Channel,
Center Freq, 300, MHz.
b. Press SPAN X Scale, Span,
500, kHz.
c. Press BW, Res BW, 30,
kHz.
d. Press Sweep/Control,
Sweep Time, 20, ms.
144
Notes