Rohde & Schwarz R&S SMW200A - About ARB

Configuring the Internal Baseband Source
R&S
®
SMW200A
297User Manual 1175.6632.02 ─ 30
For more information, see data sheet.
5.7.2 About ARB
This section provides background information on the ARB functionality and the impact
of the provided settings.
For a description of the multi-carrier, multi-segment and multi-carrier continuous wave
functions, refer to:
●
Chapter 5.11, "Generating Multi-Carrier Signals", on page 381
●
Chapter 5.10, "Generating Multi-Segment Waveform Files", on page 351
●
Chapter 5.12, "Generating Multi-Carrier Continuous Wave Signal", on page 398
5.7.2.1 Waveform Files Sources
In ARB mode, the R&S SMW uses ARB waveform files to obtain the digital I/Q data of
the baseband signal. The R&S SMW can play back any waveform file saved on a net-
work drive but it can also generate and play back simple waveforms for test purposes.
What is a waveform?
A waveform is a file with specified file format containing raw IQ samples. The IQ values
are calculated in advance and saved in waveform files with a predefined extension
*.wv.
When waveforms are created by the R&S SMW, the instrument inserts a waveform
header at the beginning of each created ARB file. The header of the generated I/Q
data files consists of "tags" which are enclosed in braces { }.
For detailed description on all available tags and for information on how to query them
or to create waveforms manually, refer to Chapter 5.7.5, "Tags for Waveforms, Data
and Control Lists", on page 327.
Waveform file sources
Depending on whether the R&S SMW creates the waveform files itself or not, the fol-
lowing waveform file sources can be distinguished:
●
Internally generated waveforms
The ARB generator enables the calculation and the generation of multi-segment
and multi-carrier waveform files. The ARB generator provides also a built-in func-
tion to create a test waveform (e.g. a sine or rectangle signal) and keep it as a file
or in the RAM.
Several digital standards provide the special function "Generate Waveform File".
With this function, the calculated signals are saved as a waveform file that you can
play back using the ARB generator.
●
Externally generated or created waveforms
The ARB generator processes externally created waveform files, for example:
– The waveform files generated by the software R&S WinIQSIM2, the
R&S ARB Toolbox, the R&S Pulse Sequencer
Using the Arbitrary Waveform Generator (ARB)