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Modulation Depth Setting
Modulation depth indicates the extent of amplitude variation and is expressed as percentage. Suitable setting range
of AM modulation depth is 0% to 120%, and the default is 100%. When modulation depth is set to 0%, the constant
amplitude (a half of the carrier wave amplitude that has been set) is output. Output amplitude changes as
modulation waveform changes when modulation depth is set to 100%. The instrument output a peak-peak voltage
less than ±5V (
is connected with 50Ω terminal) when modulation depth is more than 100%. If need to change, press
Parameter
→Modulation Depth in amplitude function interface. When modulation source is external, output
amplitude of the instrument is controlled by ±5V signal level of external modulation input terminal (Input/CNT probe)
in rear panel. For example, if modulation depth value in parameter list has been set to 100%, AM output amplitude is
the maximum when external modulation signal is +5V, AM output amplitude is the minimum when external
modulation signal is -5V.
Comprehensive Example
Firstly, make the instrument work in amplitude modulation (AM) mode, then set a sine wave with 200Hz from the
internal of the instrument as a modulation signal and a square wave with frequency of 10kHz, amplitude of 200mVpp
and duty cycle of 45% as a carrier wave signal. Finally, set modulation depth to 80%. Specific steps are seen as
following:
1) Enable Amplitude Modulation (AM) Function
Press Menu
→Modulation→Type→Amplitude Modulation in turn.
