TFG2900A Series Function/Arbitrary Waveform Generator Users’ Guide
Suin Instruments Co., Ltd
36
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 0Vdc, sum amplitude’s displaying value will match with the actual sum amplitude.
3.7.7 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.
3.8 Frequency-shift keying (FSK) Modulation
In FSK modulation, output signal’s frequency will jump alternatively between ‘Carrier frequency’
and ‘Hop frequency’. Jumping speed depends on shift keying rate.
3.8.1 Function selection
: Press
【
Modulate
】
to enter modulation function, and then press
〖
Type
〗
to display modulation type menu, press
〖
FSK
〗
〖
4FSK
〗
〖
nFSK
〗
modulation type will be FSK,
4FSK, nFSK, and display the FSK waveform’s diagram and menu.
3.8.2
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
it’s parameter. Press
【
Modulate
】
to enter modulation parameter setting interface to set its
parameter.
3.8.3 Hop frequency
: FSK modulation is similar to square’s FM modulation. Hop frequency is
similar to frequency deviation. The difference is FM modulation’s frequency deviation is carrier
frequency plus an offset, whose setting range has relationship with carrier frequency; while hop
frequency can be set in the full frequency range randomly, without relationship with carrier
frequency. Press
〖
HopFreq
〗
, you can set its value.
You can set one hop frequency in FSK, and carrier frequency and hop frequency output
alternately.
You can set 3 hop frequencies in 4FSK, and carrier frequency and hop frequency 1, 2, 3 output in
order.
You can also set 3 hop frequencies in nFSK, carrier frequency and three hop frequency output
randomly.
3.8.4 FSK rate
: Press
〖
FSK Rate
〗
〖
4FSK Rate
〗
〖
NFSK Rate
〗
, you can set frequency shift keying