Rohde
&
Schwarz
R&S®DDF255 Digital
Direction Finder
9
Recording and
replaying of up
to 80 MHz wide
I/Q data
Never miss an event: activation of recordings with
flexible realtime event capture (REC)
Rare, short-time signals are difficult to record and ana
-
lyze. Yet these signals are of significant interest. The
R&S®DDF255-RR option includes a configurable realtime
event capture (REC) that can be used to activate I/Q data
recording. The R&S®DDF255 records only events defined
as relevant by the user. The user decides how the defined
mask is used – either the trigger is activated when a sig
-
nal enters or leaves the predefined mask, or the trigger
remains active as long as a signal is within the mask. As
a result, even events in the nanosecond range can be reli
-
ably detected using the R&S®DDF255.
Signals as received from an antenna: all receiver
functions available when replaying I/Q data
Equipped with the R&S®DDF255-RR option, the
R&S®DDF255 records I/Q data up to the full 80 MHz band
-
width and stores it in the internal memory. The recorded
data is played from memory directly on the instrument. All
receiver functions are available when replaying I/Q data
(demodulation of analog modulated signals, setting of
DDCs and ITU-compliant measurements). The user sets
all parameters as if in live mode. All changes are imme
-
diately adopted without additional calculation time, as if
the signal was directly received from an antenna. I/Q data
replay is limited only by the recording bandwidth and time
limits. The recorded I/Q data can be stored on external
storage media (e.g. USB flash drive) and later loaded into
an R&S®DDF255 for analysis.
Detailed display: replay of I/Q data with increased
time resolution
When analyzing digital signals, radar pulses and short-
time emissions, users are interested in the time behavior
of the signal. When replaying I/Q data, the time resolu
-
tion in the waterfall diagram can be increased as far as the
nanosecond range per line. The R&S®DDF255 is therefore
able to display even very short events with high resolu
-
tion and provide a detailed overview of the spectral signal
characteristics.
Realtime replay of recorded data
Recorded data is replayed in realtime in the receiver. No
wait or delay time is required for redisplaying recorded
signals, e.g. after parameter changes – for maximum user
convenience.