Rohde & Schwarz SME02 - QPSK Modulation; Spectrum

Test Procedure SME
1038.6002.02 5.32 E-13
5.2.34 QPSK Modulation
5.2.34.1 Spectrum
Caution: - The LEVEL-PRESET calibration (see service manual, stock no. 1039.1856.24) must be
carried out before this measurement.
- The delay adjustment for QPSK (see service manual, stock no. 1039.1856.24)
should be checked and renewed if necessary before the measurement.
Test equipment Spectrum analyzer (Section 5.1, item 2)
Test setup Connect spectrum analyzer to the RF output socket of the SME.
Measurement À Settings at the SME
- Carrier frequency 836 MHz, in the case of SME03/06 1513
MHz
- Level 0 dBm,
in menu DIGITAL MOD/QPSK
- SOURCE PRBS,
- PRBS 23 bit,
- SELECT STANDARD NADC
À Settings at the spectrum analyzer
- Center frequency 836 MHz, with SME03/06 1513 MHz,
- Span 300 kHz,
- Resolution bandwidth 3 kHz,
- Video bandwidth 100 Hz.
A spectrum according to Fig. 5-2 must be visible at the spectrum
analyzer which adheres to the tolerances in the following table (The
reference level is at the center frequency):
Offset frequency Level
0 kHz 0 dB (reference)
30 to 50 kHz < -40 dB
> 50 kHz < -50 dB