Rohde & Schwarz SME02 - Settling Time

Test Procedure SME
1038.6002.02 5.8 E-13
5.2.3 Settling Time
Test equipment
- Spectrum analyzer with video output (Section 5.1, item 2)
- Storage oscilloscope (Section 5.1, item 3)
- Controller (Section 5.1, item 4)
Test principle The spectrum analyzer is operated as an edge demodulator with a
0-Hz span. A controller transmits starting and stop frequency via the
IEC bus. The storage oscilloscope is connected to the video output of
the analyzer and triggered by the positive edge on the EOI line of the
IEC bus. If the controller switches over from the starting to the stop
frequency, the settling procedure is displayed on the screen of the
storage oscilloscope..
Test setup
×
Ø
S M E
RF
Video
Controller
Analyzer
IEC bus
10-MHz reference
Oscilloscope
Preparing measurement
À Synchronize the reference frequencies of SME and analyzer.
À Establish IEC bus and RF connections.
À Connect storage oscilloscope to the video output of the analyzer.
À Apply trigger connection to the EOI-line (pin 5) of the IEC bus.
À Settings at the SME
- Stop frequency unmodulated
- Level 0 dBm
À Settings at the storage oscilloscope
- Time base 2 ms/div
- Sensitivity corresponding to the video output of the analyzer,
- Trigger free-running with respect to calibration.
- Settings at the spectrum analyzer
- Reference level 5 dBm,
- Amplitude scale 1 dB/div,
- Resolution bandwidth to 3 kHz,
- Video bandwidth 100 kHz,
- Span 10 kHz
À Now increase the center frequency, starting from the stop
frequency, until the visible filter edge runs through the central point
of the screen.
À The span can now be reduced to 0 Hz and the frequency scale be
calibrated at the (free-running) oscilloscope by means of steps of
100 Hz at the SME.