Ceyear 4051 Series, User Manual

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4. Operating Instruction
4.2 Advanced operation guide
118
4051 Series Series Signal Analyzer can clearly display AM signal signal waveform via following operations:
 Obtain stable trace by setting trigger conditions on the modulation envelope and sweep demodulated
waveform synchronously with video trigger if signal modulation is stable;
 Apply linear display in AM measurement to avoid distortion of logarithmic display caused during signal
demodulation;
 Observe AM signal modulation speed via sweep time;
 Set resolution bandwidth and video bandwidth based on measured signal bandwidth.
In the following section, it will be explained how to measure AM and FM signals, how to display signals on
the analyzer and how to monitor AM and FM broadcasting signals.
4.2.6.2 Measure modulation speed and depth of AM signals with RF spectrum
AM signals can be generated by one signal generator and demodulated by connecting one antenna to RF input
port of the analyzer. The AM signal in this example is produced with a signal generator.
Step 1. connect output of the signal generator to the RF input port of the analyzer:
 Set the signal generator with an AM signal with output carrier of 100 MHz, amplitude of -10 dBm,
modulation depth of 5% and modulation speed of 34 kHz.
Step 2. set center frequency of the analyzer as 100 MHz and frequency span as 500 MHz:
 Press
【
Mode
】
and [Spectrum].

Press 【 Preset 】 .
 Press
【
Frequency
】
, [Center Freq] and enter 100MHz.
 Press
【
Span/X Axis
】
, [Span] and enter 500kHz.
Fig. 4.33 AM signal