50
PM:DEViation {<deviation in degrees>
︱
MINimum|MAXimum }
PM:SOURce {INTernal|EXTernal}
PM:STATe ON
4.10 FSK Modulation
G5100A provides the capability to output FSK (Frequency-Shift Keying)
modulation where the frequency of the waveform shifts between two
frequencies (called “carrier frequency” and “hop frequency”). The
shifting rate is determined by the internal or external modulating signal.
Carrier Waveform
The default carrier waveform is sine. One may also choose from square,
ramp and arbitrary waveforms but not pulse, noise and dc waveforms.
The default carrier frequency is 1 kHz for all waveforms. Each carrier
waveform has its own acceptable range of frequencies. Refer to the table
in Section 3.4 “To Set Output Frequency/Period” for details.
Modulating Waveform
G5100A accepts either internal or external modulating source but not
both at the same time. The default source is internal, and the only choice
is square wave with a 50% duty cycle. When external source is selected,
the carrier waveform is modulated with an external waveform present at
the
Trig In
connector on the rear panel. The
Trig In
connector does not
have adjustable edge polarity when used in FSK.
“Hop” Frequency
The default is 100Hz for all functions. Each carrier waveform has its own
acceptable range of allowable hop frequency as follows.
•
Sine: 1
μ
Hz to 50 MHz(at carrier frequency = 1
μ
Hz).
•
Square: 1
μ
Hz to 25 MHz(at carrier frequency = 1
μ
Hz).
•
Ramp: 1
μ
Hz to 200 kHz(at carrier frequency = 1
μ
Hz).
•
Arbitrary: 1
μ
Hz to 10 MHz(at carrier frequency = 1
μ
Hz).
When external source is selected as the source of modulating waveform,
