R&S SM300 - Level; Level Frequency Response and Linearity

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