Rohde & Schwarz R&S SMU200A, Service Manual

Page: 56 / 294

Test Procedures R&S SMU200A
1007.9845.82 1.30
E-12
Amplitude Modulation
Uncertainties
Test assembly
See section "
Standard Test Assembly for Analog Modulations
",
page 1.3 .
Measurement
Settings on DUT:
RF On
Level 0 dBm:
Amplitude Modulation menu:
Source Internal
Test Method Spectrum
Measurement
Measure the carrier power
RF
P
and the power of the two sidebands
mod f RF
P
and
mod f RF
P
+
with the spectrum analyzer. Calculate the
modulation depth as mean value of both sidebands.
RF
f RF f RF
P
P P
A
mod mod
+
+
=
Test Method Demodulation
Measurement
Settings on R&S FSQ:
AMPTD / REF LEVEL test level + 6 dB ,
FREQ / CENTER test frequency
FMDEMOD,
FMDEMOD
ON,
RESULT DISPLAY / AM
DEMOD BW > 3* fmod,
RANGE / DEVIATION PER DIV 20 %
MEAS TIME 3/fmod
for distortion (up to 3
rd
harmonic)
RESULT DISPLAY / AM / AF SPECTRUM
DEMOD BW > 7 * fmod,
MEAS TIME 16/fmod
Recommended settings
Resolution of the setting
Measurement at f
mod
= 1 kHz, RF 150 MHz, test level P
min
+3 dBm of
m = 10% to 96% in at least 10 steps.
RF frequency response at f
mod
= 1 kHz, m = 80%, test level P
max
,
Recommended test frequencies: 5, 150, 1500, 1501, 2200, 2999,
3001, 4399, 4401, 6000 MHz.