User manual

5-14 Return to Section Topics 3390-900-01 Rev. C / January 2009
Section 5: Waveform Output Operations Model 3390 Arbitrary Waveform Generator User’s Manual
6. Press the Graph key to view the waveform parameters in the graph mode.
To set up phase modulation from a remote interface:
FUNCtion {SINusoid|SQUare|RAMP|USER}
FREQuency {<frequency>|MINimum|MAXimum}
VOLTage {<amplitude>|MINimum|MAXimum }
VOLTage:OFFSet {<offset>|MINimum|MAXimum }
PM:INTernal:FUNCtion {SINusoid|SQUare|RAMP|NRAMp|TRIangle|NOISe|USER}
PM:INTernal:FREQuency {<frequency>|MINimum|MAXimum}
PM:DEViation {<deviation in degrees>|MINimum|MAXimum }
PM:SOURce {INTernal|EXTernal}
PM:STATe {OFF|ON}
Frequency-shift keying modulation
Frequency-shift keying (FSK) modulation allows the frequency of the carrier waveform to shift
between two discrete frequencies (the carrier frequency and the hop frequency). The shifting rate
is determined by the modulating signal.
Carrier waveform
The default carrier waveform is sine. You can also choose square, ramp and arbitrary waveforms.
The default carrier frequency is 1 kHz for all waveforms. Each carrier waveform has its own
acceptable range of frequencies. Refer to Table 4-1: Waveform function frequency ranges
for details.
Modulating waveform
The Model 3390 accepts either an internal or external modulating source.
The default source is internal, and the internal modulating waveform is a square waveform with a
50% duty cycle.
Select the external modulating source to modulate the carrier waveform with an external signal
present at the Trig In/Out, FSK / Burst connector on the rear panel.
Hop frequency
The default frequency is 100 Hz. Each waveform has a different acceptable range:
• Sine: 1 μHz to 50 MHz (at carrier frequency = 1 μHz)
• Square: 1 μHz to 25 MHz (at carrier frequency = 1 μHz)
• Ramp: 1 μHz to 200 kHz (at carrier frequency = 1 μHz)
• Arbitrary: 1 μHz to 10 MHz (at carrier frequency = 1 μHz)
Choosing the external source means the modulation is controlled by the signal levels of the
external waveform. When the external waveform is at the logic "low" level, the output is at the
carrier frequency. When the external waveform is at the logic "high" level, the output is at the
hop frequency.
FSK rate
The FSK rate is the rate at which the output frequency shifts between the carrier frequency and the
hop frequency when internal source is selected. The default FSK rate is 10 Hz and the range is
from 2 mHz to 100 kHz.