Basics on I/Q Data Acquisition and Processing
R&S
®
FSV/A3000 I/Q
Analyzer
37
User Manual 1178.8536.02 ─ 01
External trigger as input
If the trigger signal for the R&S
FSV/A is provided by an external device, the trigger
signal source must be connected to the R&S
FSV/A and the trigger source must be
defined as "External" in the R&S
FSV/A.
Trigger output
The R&S
FSV/A can provide output to another device either to pass on the internal
trigger signal, or to indicate that the R&S
FSV/A itself is ready to trigger.
The trigger signal can be output by the R&S
FSV/A automatically, or manually by the
user. If it is provided automatically, a high signal is output when the R&S
FSV/A has
triggered due to a sweep start ( "Device Triggered" ), or when the R&S
FSV/A is ready
to receive a trigger signal after a sweep start ( "Trigger Armed" ).
Manual triggering
If the trigger output signal is initiated manually, the length and level (high/low) of the
trigger pulse is also user-definable. Note, however, that the trigger pulse level is always
opposite to the constant signal level defined by the output "Level" setting, e.g. for
"Level" = "High", a constant high signal is output to the connector until the "Send Trig-
ger" button is selected. Then, a low pulse is provided.
4.7
I/Q Data Import and Export
Baseband signals mostly occur as so-called complex baseband signals, i.e. a signal
representation that consists of two channels; the in phase (I) and the quadrature (Q)
channel. Such signals are referred to as I/Q signals. The complete modulation informa-
tion and even distortion that originates from the RF, IF or baseband domains can be
analyzed in the I/Q baseband.
Importing and exporting I/Q signals is useful for various applications:
●
Generating and saving I/Q signals in an RF or baseband signal generator or in
external software tools to analyze them with the R&S
FSV/A later
●
Capturing and saving I/Q signals with an RF or baseband signal analyzer to ana-
lyze them with the R&S
FSV/A or an external software tool later
As opposed to storing trace data, which may be averaged or restricted to peak values,
I/Q data is stored as it was captured, without further processing. The data is stored as
complex values in 32-bit floating-point format. Multi-channel data is not supported. The
I/Q data is stored in a format with the file extension
.iq.tar
.
I/Q Data Import and Export