R&S AFQ100A
Impairments Block
1401.3084.32 4.40
E-3
Impairments Block
Introduction
Impairment of the digital I/Q signal can be used, for example, to compensate the distortion of a test
object or to check the effect of a distorted signal on a test object.
The
I/Q Impairment
dialog for setting the digital I/Q impairments is opened either in the
Impairments
function block or by selecting
Impairments
in the
Edit
menu.
Impairment Settings Dialog
State
Switches I/Q impairment On or Off.
Remote-control command:
SOUR:IMP:STAT ON
I Gain (dB) / Q Gain
(dB)
Sets a gain in the I or Q path, respectively.
The entry is made in dB, where 1 dB offset is roughly 12 % according
to the following:
Imbalance [dB] = 20×log
( | Gain
Q
| / | Gain
I
|)
An ideal I/Q modulator amplifies the I and Q signal path by exactly the
same degree. The imbalance corresponds to the difference in
amplification of the I and Q channel and therefore to the difference in
amplitude of the signal components. In the vector diagram, the length
of the I vector changes relative to the length of the Q vector.
