User Manual

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5.5.5 Modulating Source
The waveform generator will accept an internal or external modulation source for PM. Press 〖Source
Int/Ext〗softkey. It’s available to set modulating frequency and modulating waveform if ‘Internal’
source is selected. But if you select External source, the carrier waveform is modulated with an
external waveform. The frequency deviation is controlled by
the ±5 V signal level present on the rear-panel Modulation In connector.
5.6 Pulse Width Modulation (PWM)
In Pulse Width Modulation (PWM), the width of a pulse waveform is varied by the instantaneous
voltage of the modulating waveform. You must select PWM before setting up any of the other
modulation parameters. Press 【Modulate】key then select the PWM using the 〖Mod Type〗softkey.
The PWM waveform is output using the present settings for the carrier frequency, modulating
frequency, output amplitude, and offset voltage.
5.6.1 Set Carrier
Firstly, set the frequency, amplitude and offset of Carrier Waveform. The waveform generator only
allows PWM to be selected for a pulse waveform.
5.6.2 Pulse Width Deviation
The PWM deviation setting represents the peak variation in width of the modulated pulse waveform.
Press 〖Width Dev〗softkey then enter the desired value using the knob or keypad. If at positive peak
value, the pulse width of output signal equals to setting value of pulse width plus deviation. If at
negative peak value, the pulse width of output signal equals to setting value of pulse width decrease
a deviation.