Rohde & Schwarz SMU200A - Spectral Purity

Test Procedures R&S SMU200A
1007.9845.82 1.12
E-12
Spectral Purity
Harmonics
Test equipment Spectrum analyzer (Table 1-2, item 24)
Test setup Connect the spectrum analyzer to the RF output of the DUT.
 Synchronize reference frequencies of analyzer and DUT
.
Recommended settings on the
spectrum analyzer
 Reference level = test level + 3 dB, 10 dB/div.
Span 0 Hz,
Resolution bandwidth 1 kHz,
Video bandwidth 30 Hz,
Sample detector
Note:
These values are typical values that depend on the analyzer used.
The necessary measurement resolution must be verified prior to the measurement.
Recommended frequencies
 According to Table 1-
4
Measurement  Settings on DUT:
- Fr
equency: test frequencies, unmodulated
- Level: level
max
according to data sheet (depending on
configuration of the unit)
 First measure the level of the fundamental as a reference. Then fi
nd
s
ignals at twice and three times the carrier frequency.
 The harmonic spacing is the measured level referred to the
fundamental (dBc = referred to the carrier).
Subharmonics
Test equipment Same as for harmonics suppression
Test setup Same as for harmonics suppression
Recommended frequencies  1501 MHz, 1550 MHz to 6000 MHz in 50 MHz steps
Measurement
 First the level of the fundamental is measured as reference, t
hen a
s
ignal is searched for at 0.5*test frequency and 1.5*test frequency.
 The subharmonic spacing is the measured level referred to the
reference level (dBc = referred to the carrier).