User manual

3390-900-01 Rev. C / January 2009 Return to Section Topics 5-13
Model 3390 Arbitrary Waveform Generator User’s Manual Section 5: Waveform Output Operations
The default source is internal with a default frequency of 100 Hz (the acceptable range is 2 mHz to
20 kHz). The default internal modulating waveform is a sine waveform, but you can also select
from the following:
• Square waveform with 50% duty cycle
• URamp (up or positive ramp with 100% symmetry)
• DRamp (down or negative ramp with 0% symmetry)
• Triangle waveform (ramp with 50% symmetry)
• Noise waveform
• Arbitrary waveform (limited to 4 K points with automatic decimation)
Select the external modulating source to modulate the carrier waveform with an external signal
present at the Modulation In connector on the rear panel.
Phase deviation
The phase deviation represents the peak variation in the phase of the modulation output, based
on that of the carrier waveform. The range of the phase deviation is from 0º to 360º, and the
default is 180º.
Choosing the external source means the modulation is controlled by the specified phase deviation
and the ±5 V signal levels of the external waveform. When the external waveform is at +5 V, the
output will reach maximum positive phase deviation. When the external waveform is at -5 V, the
output will reach maximum negative phase deviation.
To set up phase modulation:
1. Select the carrier waveform (Sine, Square, Ramp, or Arb). Follow the instructions for
setting up that specific waveform as given in this publication. Refer to Section 4, Setup
Basics for assistance.
2. Press the Mod key to access the modulation menu.
3. Press the soft key under Type; then press the soft key under PM to select phase modulation
(Figure 5-13). A phase modulation output will be generated with the set parameters.
Figure 5-13:
Press the soft keys corresponding with PM
4. Press the soft key under Src to select between internal source (Int) and external source
(Ext) for the modulating waveform (Figure 5-13). If internal source is selected:
a) Press the soft key under Shape to select the modulating waveform. If arbitrary
waveform (Arb) is chosen, the instrument will use the currently selected arbitrary
waveform. Press the Mod key to see which arbitrary modulating waveform is
currently selected.
b) Press the soft key under PM / Freq. Use the navigation wheel with the cursor keys
to change the value, and then press another soft key to finish the entry and exit. Or
use the numeric keypad to enter a desired value and then press the soft key under
the desired units to finish the entry, or the soft key under Cancel to cancel the
changes.
5. Press the soft key under Phase / Dev (Figure 5-13). Use the navigation wheel with the
cursor keys to change the value, and then press another soft key to finish the entry and exit.
Or use the numeric keypad to enter a desired value and then press the soft key under deg
to finish the entry, or the soft key under Cancel to cancel the changes.