Test Procedures R&S SMB
1407.0806.82 1.34 E-5
AM Frequency Response
Test assembly See section "Standard Test Assembly for Analog Modulations",
page 1.3.
Measurement
Settings on DUT:
RF On
L
evel 0 dBm
Amplitude Modulation menu:
Source External
External Coupling DC
AM depth 60%.
Settings on R&S FSQ:
AMPTD / REF LEVEL 6 dBm
FREQ / CENTER test frequency
FM DEMOD,
FMDEMOD ON,
RESULT DISPLAY AM
RESULT DISPLAY AF SPECTRUM
DEMOD BW 200 kHz,
RANGE DEVIATION PER DIV 20 %
MEAS TIME D 16/fmod s
Vary the carrier frequency from 1 MHz to RF
max
. Recommended
test frequencies 1 MHz, 46.87 MHz, 186.9 MHz, 1.1 GHz, 2.2GHz,
3.2 GHz, 6 GHz.
Settings on the signal generator:
- LF Output ON
- LFGen Voltage 1 V (V
peak
).
Set the generator frequency to the frequencies given below and
measure the modulation depth in RMS.
Gen. frequency 10 Hz 100 Hz 1 kHz
10 kHz 50 kHz
MEAS TIME 1.6 s 0.2 s 0.2 s 0.2 s 0.2 s
The modulation frequency response in dB is the difference
between the greatest and the smallest modulation depth m
max
and m
min
:
m
max-min
= 20 * log
10
(m
max
) - 20 * log
10
(m
min
)
Repeat the measurement at RF = 1 GHz with the setting
Amplitude Modulation External Coupling AC
Repeat the measurement at RF = 1 GHz with the internal
modulation generator with the setting
Amplitude Modulation Source Internal.
To Next Page
Loading...
