TFG2900A Series Function/Arbitrary Waveform Generator Users’ Guide
Suin Instruments Co., Ltd
33
channel’s
《
Mod In I
》
port. When external modulation signal’s amplitude is 5Vpp, DC offset is
0Vdc, displaying value of modulation depth will match with the actual modulation depth.
3.4.7 Sync output
: Sync signal’s duty cycle is 50%, sync signal’s frequency is equal to
modulation frequency, sync signal’s phase takes modulation signal’s phase as reference.
3.5 Phase Modulation
In phase modulation, carrier’s phase changes with the modulation signal’s transient voltage.
3.5.1 Function selection
: Press
【
Modulate
】
to enter modulation function, and then press
〖
Type
〗
to display modulation type menu, press
〖
PM
〗
, modulation type will be PM, and display the phase
modulation’s waveform diagram and phase modulation menu.
3.5.2
Carrier setting
: Usually Sine is used as carrier wave. Of course other built-in waveforms
can also be used, but some are not suitable. Press
【
CH1
】
to enter carrier parameter interface to set
carrier’s parameter. Press
【
Modulate
】
again to enter modulation parameter setting interface to set
its parameter.
3.5.3 Phase deviation
: Press
〖
PhaseDev
〗
, you can set phase difference value. Phase deviation
means carrier phase’s variation quantity when modulation signal reaches full amplitude in the
phase modulation. In modulation signal’s positive full amplitude value, output signal’s phase
increases a phase difference. While in negative full amplitude value, the phase decreases a phase
difference.
3.5.4 Modulation frequency
: Press
〖
ModFreq
〗
to set modulation signal’s frequency value.
Modulation frequency is usually far lower than carrier frequency.
3.5.5 Modulation waveform
: You can use most of built-in waveform as modulation waveform,
but some of them may be not suitable. Press
〖
Shape
〗
to choose modulation waveform. After
choosing it, press
〖
Back
〗
to return to modulation menu.
3.5.6 Modulation source
: Press
〖
Source
〗
to choose modulation source. If ‘Internal’ is chosen,
instrument will use internal modulation source, modulation frequency and waveform setting is
effective. If ‘External’ is chosen, instrument will use external modulation source, modulation
frequency and waveform setting will be ignored. Input modulation signal from rear panel’s
《
Mod
In I
》
port of current channel. When external modulation signal’s amplitude is 5Vpp, DC offset is