R&S SM300
Manual Test Procedure
Version 04
73
Service Manual SM300: 1147.1652.00
Instrument Part No SM300: 1147.1498.03
2.4.4 LEVEL
2.4.4.1 Level Frequency Response and Linearity
Test equipment
Power meter (Table measuring equipment and accessories, item 6)
Precision attenuator (Table measuring equipment and accessories,
item 7)
Spectrum analyzer (Table measuring equipment and accessories,
item 2)
Low-noise preamplifier (Table measuring equipment and accessories,
item 13)
Test method for level in measurement range of power meter (up to approx.- 20 dBm)
Test setup
Connect power meter to RF output connector
Settings on SM300
Test frequencies: 10.4 MHz, 249 MHz, 1549 MHz, 2989 MHz
Test level: 13 dBm, 10 dBm, 5 dBm, 0 dBm, -5 dBm, -10 dBm, -15 dBm,
-20.0 dBm
Settings on power
meter
Carry out a ZEROING prior to level measurements
The level on SM300 is switched off with RF OFF
Measurement
Measure level at test frequencies
The frequency response is the difference between the highest and lowest
measured value
The level error is the deviation from the set value
Measurement procedure for low levels (> -115 dBm)
Caution
A prerequisite for correct measurements is that the components used are
completely RF-shielded
Test method
Levels below the measurement range of the power meter can be measured
by a comparison measurement using a precision attenuator and a sensitive
test receiver or spectrum analyzer. The reference is formed by a level
measurement for example at 10 dBm by means of the power meter.
Test setup
Connect a precision attenuator to the RF connector of SM300
Connect the attenuator output to a spectrum analyzer via RF-leakage-proof
test cables
Connect 10 MHz references with each other
Settings on SM300
Test frequencies: 10.4 MHz, 249 MHz, 1549 MHz, 2989 MHz
LEVEL 10 dBm
REF to external
Settings on test
receiver or analyzer
Center frequency = test frequency
Span = 0 Hz
Settings on precision
attenuator
Attenuation = 125 dB
