SIGLENT
SSG5000X Service Manual 25
5) Set the modulation deviation to 500 kHz.
6) Set the modulation rate to 1 kHz.
7) Set the modulation waveform to
“Sine”.
8) Enable the modulation output switch
MOD
.
9) Enable the RF output switch
RF
.
3. Configure the Signal Analyzer:
1) Select the
Analog Demod
mode.
2) Select the
FM
analog demodulation.
3) Press
Meas Setup
->
Auto BW & Scale
.
4) Set the span to 2 MHz.
5) Set the Channel BW to 1.5 MHz.
6) Set the RF Res BW to 300 Hz.
4. Read the results of the demodulated signal in the FM analog demodulation
test interface of the signal analyzer. Record the measurement results
(Pk -
Pk)/2
and
Distortion
.
Note:
the value
(Pk - Pk)/2
represents the peak of the low frequency signal
after FM demodulated.
5. Calculate the modulation accuracy and the distortion using the formulas:
FM Accuracy = |(Pk - Pk)/2
– 500 kHz|
,
FM Distortion = Distortion
.
Next, compare the calculation results with the specifications.
Test Record Form
SSG5000X
Output
Frequency
Test Item
Measure
ment
Calculated
Result
Limit
Pass/ Fail
1 GHz
FM Accuracy
[1]
<2% of
20 Hz
FM Distortion
[2]
<0.5 % (nom.)
Note:
[1] FM Accuracy = |(Pk - Pk)/2
– 500 kHz|
[2] FM Distortion = Distortion value in the FM analog demodulation test interface
