Configuring the Internal Baseband Source
R&S
®
SMBV100B
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User Manual 1178.4460.02 ─ 03
In general the I/Q samples are located on a deformed circle which is confined to
the dashed square in the upper diagrams.
●
Rect Test Signal:
Rectangle signal with selectable but equal On and Off periods
and amplitude. The period is defined by the selected frequency: <Period> = 1 /
"Frequency".
The signal is mapped on both the I and Q samples. This results in two distinct
points in the I/Q plane. The "Offset DC" shifts both points along the diagonal I(t) =
Q(t).
●
Const I/Q Test Signal:
Continuous test signal with constant IQ and constant Clock
Frequency of 10 KHz. The values for each I and Q components are selectable but
constant. They are defined as a decimal number, which is decimal-to-binary con-
verted internally. The signal is provided as a 16-bit wide digital signal for both I and
Q channels.
Converted to analog, the signal is output directly at the BNC connectors I and Q
outputs of the instrument.
3.6.2.3
Waveform Sample Rate
The Arbitrary Waveform Generator includes a resampling unit that interpolates the
input samples to reach a target digital output I/Q sample rate before digital-to-analog
conversion (DAC). The input sample rate f
input
is retrieved from the waveform (the
default sample rate tag) or is defined by the corresponding parameter in the ARB user
interface.
depicts the stages involved in the processing and resampling of a
waveform in the ARB.
Figure 3-12: Processing of the waveform files in the ARB
Using the Arbitrary Waveform Generator (ARB)
