Instrument Function
R&S
®
SMU200A
377Operating Manual 1007.9845.32 ─ 15
The three Baseband Generator options feature different ARB memory sizes (see data
sheet). Apart from the memory size, however, the three options offer the same function-
ality, either one can be installed.
In the case of two-path instruments, at least one further Baseband Generator option is
needed for waveform output in the second path. Using this option a waveform can be
read in on path B and then either routed via path A or added to the signal on path A with
a frequency offset that can be set.
When path B is fully expanded with a second option Baseband Main Module (R&S SMU-
B13) and an RF section frequency option (B20x) the waveform can be output on RF
output B.
Sources for waveform files
The R&S Signal Generator can generate ARB waveforms internally. The ARB generator
enables the calculation and the generation of multi segment and mutli carrier waveform
files. Several digital standards provide the special function "Generate Waveform File" and
enable the calculation and storage of the signal as a waveform file that can be afterwards
processed by the ARB generator.
The ARB can also process externally generated waveform files, e.g. the waveform files
generated on a PC by the Windows software package R&S WinIQSIM2 or signals cal-
culated using a mathematical program such as Matlab. For more information, see Appli-
cation Note 1MA28, “IQWizard - I/Q Signal Measurement and Conversion”, which can be
obtained from the Rohde&Schwarz web site at http://www.rohde-schwarz.com.
The externally generated waveform files can be loaded into the instrument via one of the
available interfaces (USB, LAN or GPIB).
Multi segment and multi carrier waveforms
To fulfill the requirements of some test systems and to enable rapid alternation between
different waveforms with differing test signals, the R&S Signal Generator provides the
functionality to generate multi segment waveform files. A multi segment waveform is a
combination of multiple waveforms called segments. Each segment represents a com-
pletely independent waveform that can be output with its own marker and clock settings.
The entire multi segment waveform is loaded into memory. The segment intended to be
output at any given moment can be selected by the user. It is therefore possible to alter-
nate between the individual waveform segments without experiencing any delay due to
the loading operation.
There are however additionally requirements conserning the clock settings if some spe-
cial triggering is necessary.
If very high switchover speeds are required, the test signals can be continuously scrolled
through with the aid of an external trigger or by applying a predefined “play list”. For this
purpose the segments must have a common sample rate. If the combined waveforms
have different sample rates, they can be adapted to a common sample rate by resam-
pling. By the same procedure the instantaneous amplitude of the various waveforms can
be scaled to a common RMS level.
Typical applications for the multi segment mode are described in the section chap-
ter 5.8.4.2.7, "Typical Applications for Multi Segment Waveforms", on page 411.
Baseband Signal - Baseband Block
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