Instrument Function
R&S
®
SMBV100A
325Operating Manual 1407.6062.32 ─ 08
below). After the DAC the signal is finally limited to a maximum bandwidth of 120 or 60
MHz respectively.
Waveforms generated by the R&S WinIQSIM2 software can be optimized by choosing a
suitable integer oversampling factor.
In comparison with conventional ARB generators that often assume oversampling factors
of 4, the ARB generator of the R&S Signal Generator requires low oversampling factors
(see the example above), but still providing excellent signal quality in terms of EVM and
ACP.
A reduced sample rate saves significantly the amount of memory or allows an increased
signal cycle time, vice versa.
Dependency between the number of marker signals and the waveform length
The R&S Signal Gererator provides the possibility to define marker signals, that are sent
to the marker outputs in synchronicity with the I/Q output signals. Marker singals can be
either predefined or subsequently defined; marker setting such as delay can be adjusted
in the corresponding Trigger/Marker/Clock Settings dialog.
The I/Q data and marker data are located in separate memory areas of the SDRAM and
can be independently configured wheras each marker signal requires one bit of the avail-
able memory size. In some cases, it might be usefull to generate a modulatition signal
without additional marker signal in order to increase the maximum waveform lengt.
The example below explains the dependency between the number of enabled marker
signals, the available memory size and the resulting waveform length.
The calculation for an instrument equipped with option R&S SMBV-B10 is as follow:
Memory Size 128 MB
Requred for I/Q data 2 x 16 bits = 32 bits (16 bits per I/Q
channel)
Memory for 2 enabled markers 2 x 1 bit = 2 bits
Size total 32 + 2 = 34 bits = 4.25 bytes
Baseband Signal - Baseband Block
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