November 2016
34
t
ools
& s
oftware
FFT implementations in oscilloscopes, the
R&S RTO2000 achieves a greater resolution
and display speed with its digital downcon-
version (DDC), in which the FFT calculation
can be limited to a selected frequency range.
User-friendly functions such as automated
measurements, peak lists, maximum hold
detectors and mask tests support debugging
in the spectrum. One unique characteristic is
the spectrogram, which visualizes the changes
in frequency components over time.
Another unique function is the new zone trig-
ger, which can be used to graphically differen-
tiate between events in the time and frequency
domains. Up to eight zones of any shape can
be defined and logically linked as trigger con-
ditions. A trigger is initiated when test signals
intersect defined zones or when those zones
are not touched. This makes it possible to
detect interferers in the spectrum during EMI
debugging or to separate read and write cycles
in memory controllers. The example in figure
5 shows how the zone trigger is used in the
spectrum to measure the current and voltage
load during a GSM radio burst.
The basis for the high degree of sensitivity and
dynamic range offered by the R&S RTO2000
are the low-noise frontends and the propri-
etary 10GHz single-core A/D converters. The
minimum effective noise of <100µV, the A/D
converters’ more than seven effective bits
(ENOB) as well as the channel-to-channel iso-
lation of >60dB are just a few examples. Such
characteristics make the analog channels
ideal for analyses in the frequency domain as
well as for measurements in the time domain.
Investigating signal details often requires a
higher vertical resolution. The oscilloscope
achieves up to 16 bits in high-definition (HD)
mode. In HD mode, high-quality, adjustable
low-pass filters downstream of the A/D con-
verter limit the signal bandwidth. The user
can select the appropriate combination of res-
olution and bandwidth. Even the digital trig-
ger system benefits from the high resolution
in HD mode and can trigger on the smallest
of signal details.
The oscilloscope offers not only high-perfor-
mance analog signal processing. It also fea-
tures powerful digital signal processing based
on a proprietary ASIC. Its fast parallel sig-
nal processing is clearly superior to external
PC-based postprocessing. The oscilloscope
acquires, processes and displays up to 1 mil-
lion waveforms per second, even when his-
tograms, masks or cursor measurements are
running. This capability, which is unique in
the lab oscilloscope class, is the key to fast and
successful detection of sporadic errors. The
acquisition memory can be extended up to 2
Gsamples, also unique in this class. Sufficient
memory is available for acquiring long pulse
or protocol sequences. The history function
also benefits from this memory depth because
more waveforms are available for detailed
analyses.
The oscilloscope is versatile enough to adapt
to specific applications. 2-channel and
4-channel models are available with band-
widths of 600 MHz, 1 GHz, 2 GHz, 3 GHz
and 4 GHz plus optional acquisition memory
upgrades. Bandwidth upgrades are available
for all models. All hardware options, includ-
ing the digital channels for logic analysis and
a 10 MHz OCXO reference clock, are plug-ins
that can be installed on-site. For specialized
tasks, software options can be enabled on the
oscilloscopes at any time. Available software
options include, for example, triggering and
decoding options and automated compliance
tests for serial interfaces, as well as options for
jitter, power and spectrum analysis.
In spite of its power and functional range,
the instrument remains extremely easy to
use thanks to its brilliant 12.1“ touchscreen.
The R&S SmartGrid function ensures that all
waveforms and other information are clearly
and understandably displayed. Important
tools such as cursors, measurements and
undo/redo are on a toolbar for quick access.
The app cockpit provides access to applica-
tions such as the triggering and decoding
functions, compliance and signal integrity
tests, I/Q analysis and even customer-specific
development tools. The R&S RTO simplifies
documentation of measurements. Screen-
shots, waveforms, events and instrument con-
figurations can be stored with a simple press
of a button.
n
Figure 4. Measurement of the current consumption of an embedded design in sleep mode. The
base station remains in contact with the GSM radio module via paging (short current pulses).
Figure 5. The zone trigger in the spectrum focuses the measurements on the GSM burst signals.
