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1) Internal Source
When modulation source is internal, modulation wave can be: sine wave, square wave, rising ramp wave, falling
ramp wave, arbitrary wave and noise. After enabling AM function, the default of modulation wave is sine wave. If
need to change it, press Carrier Wave
→Parameter→Type in turn.
Square wave: duty cycle is 50%
Rising Ramp Wave: symmetry degree is 100%
Falling Ramp Wave: symmetry degree is 0%
Arbitrary Wave: when arbitrary wave is modulated waveform, DDS function generator limits arbitrary wave
length as 1kpts in the way of random selection
Noise: White Gauss noise
2) External Source
When modulation source is external, parameter list will hide the modulation wave option and modulation frequency
option, and carrier waveform will be modulated by an external waveform. AM modulation depth is controlled by ±5V
signal level of external modulation input terminal. For example, if modulation depth value is 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.
Modulation Shape Frequency Setting
When modulation source is internal, frequency of modulation shape can be modulated. After enabling AM function,
range of modulation wave frequency is 2mHz~50kHz (default is 100Hz). Press Parameter
→Modulation Frequency
to change. When modulation source is external, parameter list will hide the modulation shape option and modulation
frequency option, and carrier waveform will be modulated by an external waveform. The range of modulation signal
input from external is 0Hz~ 20Hz.
