Rohde & Schwarz SMU200A - I;Q Modulation

R&S SMU200A Test Procedures
1007.9845.82 1.43
E-12
I/Q modulation
Input Impedance (VSWR)
Test equipment
See section "
Test Assembly for Output Impedance (VSWR)", page 1.5.
Test setup
 Connect the test port to the I or Q input instead of the RF output.
Measurement  Settings on DUT:
Fr
equency 900 MHz
Level 0 dBm
I/Q Settings menu:
Source Analog Wideband I/Q Input
State On
 Settings on signal generator:
- Level 10 dBm
- Carrier frequency 1 to 50 MHz in 10 steps
 Screw the VSWR bridge off and measure the level as reference level.
 C
onnect the VSWR bridge to the I input and measure the level again.
 T
he voltage ratio of test level to reference level is the output
reflection coefficient r of the DUT.
 From this, the voltage standing wave ratio (VSWR) can be calculat
ed
as
follows:
VSWR = (1+r)/(1-r)
 Repeat the measurement for the Q input
.
RF level with I/Q modulation
Test equipment - Power meter (Table 1-2, item 8)
- DC voltage source (Table 1-1, item 12)
Test setup
 Connect the power meter to the RF output socket
.
 C
onnect the DC voltage source to the I or Q input.
Measurement  Settings on DUT:
RF
On
Frequency 900 MHz
Level 0 dBm
 Measure the level without modulation as reference level
.
 I
/Q Settings menu:
Source Analog Wideband I/Q Input
State On
 Set the DC voltage source to 0.500 V and measure the level agai
n.
 T
he level difference is the required measurement value.