R&S AFQ100A Operating Manual page 153

R&S AFQ100A
I Offset / Q Offset
1401.3084.32
Sets a DC component in the I or Q path. The accessible data range
depends on the settings of the Gain text box. After entering the gain,
the instrument calculates the accessible data range of the offset,
displaying the range in a small yellow flyout window when moving the
mouse in the Offset text box. The reason is the instrument will not
output an amplitude exceeding 1.0 full scale.
An ideal I/Q modulator suppresses the carrier leakage completely
(offset = 0 percent). If an offset is entered for a component, a carrier
leakage with fixed amplitude is added to the signal. In the diagram, all
I values or Q values are offset by a fixed amplitude value depending
on the entered percentage.
Effect of offset for the I component:
Effect of offset for the Q component:
4.42
Impairments Block
E-3