Configuring the Internal Baseband Source
R&S
®
SMW200A
411User Manual 1175.6632.02 ─ 30
To observe the effect of offsetting the phase
Use the built-in real-time graphical display ("System Configuration > Graphics > Con-
stellation") and observe that the points on the I/Q constellation diagram are turning
counterclockwise.
See Chapter 9.1, "Displaying Baseband Signal Characteristics in Real-Time",
on page 597.
5.14.1.3 Impact of the Gain
The "Gain" of the different baseband sources determine the relative gain of the associ-
ated signals relative to each other.
In "System Configuration > Standard Mode", you can fade the baseband signal and
route it at the output of the fading simulator to superimpose the faded signals from the
basebands.
The real gain of the superimposed signal is measured at the output of the "Fading"
block and set with the fading parameter "Summation Ratio A/B".
See the user manual "Fading Simulator", section "Summation Ratio A/B").
The relative gain set with the parameter "Gain" in the "Baseband" block is ignored.
The real gain in a signal path depends on the following parameters along with the
defined baseband gain:
●
Signal characteristics, in particular the crest factor
●
Number of baseband sources
●
Overall RF output level.
To observe the effect of changing the gain
To verify and visualize the cumulative baseband signal, use:
●
The "System Configuration > Graphics > Power Spectrum" view.
See "To set and verify path gain and routing" on page 615.
See also Chapter 3.3.6, "Verifying the Generated Signal", on page 69.
●
The "Setup > Baseband Powers Simulation" dialog, see Chapter 9.2, "Querying
Information on the Baseband Power Levels", on page 621.
5.14.2 Baseband Offsets Settings
Access:
► Select "Baseband > Baseband Offsets" or "BB Input > Baseband Offsets".
The "Baseband Offsets" dialog provides the settings necessary to add frequency
and/or phase offset.
Moreover, you can add a path gain to the baseband signals relative to each other.
Shifting and Boosting the Baseband Signal
To Next Page
Loading...