Rohde & Schwarz SMU200A - Page 91

R&S SMU200A Test Procedures
1007.9845.82 1.65
E-12
Function External Clock
The equipment layout for generating the digital modulation signals includes the options R&S B13 (Baseband
Main Module) and R&S B10 (Baseband Generator).
Test equipment Vector Signal Generator DUT (table 1-1, pos. Pos. 5) ,
Signal Analyzer R&S FSQ with option R&S FSQ-K70
(vector signal analysis).
Test setup
 Connect CLOCK outputs of reference DUT to CLOCK inputs of tes
t
DU
T (DUT)
.

Connect signal analyzer to RF output of DUT
Test method The test DUT is supplied with a clock from the reference DUT via the
external interface. The modulated signal is extracted at the RF output of
the DUT, demodulated with the R&S FSQ and checked for EVM.
Measurement  Settings on DUT
Frequency: 100 MHz
Level: 0 dBm
Custom Digital Mod:
State ON
Data Source Pattern 010101010101
Modulation Type 8PSK
Symbol Rate 20 MHz
Filter RRC (Root-Raised-Cosine)
Roll off 0.22
Clock
Source: External
Mode: Multiple Symbol
Multiplier: 5
Global Settings
Threshold Data Input 50 Ohm
Impedance Data Input 1.5 V
 Settings on reference-DUT
Frequency: 100 MHz
Level: 0 dBm
ARB
Load Waveform any
State ON
Clock Freq 100 MHz
 Check external clock rate (Measured Extern Clock in Trigger-
Marker-Clock menu) - must be 100 MHz.
 Settings on analyzer:
VSA
FREQ CENTER: 100 MHz
AMPT / REF LEVEL 5 dBm
MODULATION SETTINGS
SYM RATE 20 MHz
MODULATION & MAPPING PSK 8PSK
MODULATION FILTER RRC RRC RRC RRC
ALPHA BT 0.22
 Check EVM in Modulation Accuracy Tabl
e.
The number of necessary measurement depends on the number of installed RF- and baseband paths, see
following table:
Installed paths
1 x RF
1 x BB
2 x RF
2 x BB
2 x RF
1 x BB
1 x RF
2 x BB
Custom Digital Modulation: external clock function
Number of measurements
1 x 1 x 1 x 1 x