Adding noise and predistortions, and impairing the signal
R&S
®
SMM100A
283
User Manual 1179.1341.02 ─ 05
4. On a connected signal analyzer, monitor the power spectrum.
5. Vary the "I/Q Offset" until the maximal carrier leakage suppression is achieved.
Adjusting the I and Q offsets is one of the possible ways to control carrier leakage.
See
Chapter 4.12.3, "How to improve signal characteristics by shifting the base-
on page 260 for other related settings.
5.3
Frequency response correction
Frequency response correction is a method, used to compensate the frequency
response influence of the test setup, for example of the cables, power combiners,
switches or mixers. In the R&S
SMM100A, you can load user-defined scattering
parameters (S-parameters) files and frequency response files and pre-process the
infernally generated baseband signal with them.
See user manual R&S
SMM-K544 User-Defined Frequency Response Correction.
5.4
Applying digital predistortion
Digital predistortion (DPD) is one of the methods, used to improve the efficiency of RF
power amplifiers. In the R&S
SMM100A, the generated digital signal can be deliber-
ately AM/AM and AM/PM predistorted.
See user manual R&S
SMM-K540, R&S
SMM-K541 Envelope Tracking and AM/AM,
AM/PM Predistortion.
Applying digital predistortion