Rohde & Schwarz R&S UPP, Руководство пользователя

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Instrument Functions
R&S
®
UPP
437 User Manual 1411.1055.32 ─ 10
input of the DUT and the time required for the signal to appear at the output of the DUT
is measured.
With this type of measurement, it is essential for the time measurement to be started
exactly when the signal appears at the input of the DUT, i.e. at the output of the gener-
ator. The internal delays of the generator and the analyzer must be taken into account
automatically. To allow measurements to be made at the D/A and A/D converters, this
synchronization must effectively extend over both domains – from analog to digital and
from digital to analog.
Just like the previous UPD and R&S UPL instruments, the R&S UPP provides a spe-
cific waveform measurement mode for this measurement task: "Gen Burst" mode. In
this operating mode, the start of the measurement (and thus the start of waveform
recording) is synchronized to the start of the generator signal (preferably Sine Burst):
●
The generator signal is muted briefly (approx. 3 ms) and then restarted with
zero
‑
degree phase (in the case of a burst signal with "Burst On")
●
The analyzer does not start recording until it receives an internal trigger signal from
the generator and the internal signal delays of the generator and analyzer being
used have expired.
As the generator signal contains an (intentional) signal dropout and reset at the start of
each measurement cycle in this operating mode, it should only be used for measuring
delays and not for measuring signal quality.
The delay of the DUT can be read directly from the waveform display by comparison
with the start of the generator signal. A sine burst signal is particularly suitable for this
type of measurement, since it has a zero level before and after the burst if the "Low
Level" value, burst duration and burst interval parameters are suitably configured.
Internal triggering to the generator signal cannot be applied if a multichannel analyzer
is used. Instead, however, one of the measurement channels – as reference and trig-
ger channel – can record the generator signal and trigger the waveform measurement
while two other channels are displayed as waveform.
Sine Burst is equally suitable for single and continuous measurements, since the trig-
ger for the next measurement is automatically re-armed by the burst pause. However,
any other type of generator signal can also be used for single measurements, since the
start of the signal can be recognized from the brief signal blanking interval. The set-
tings for operation with a sine burst signal are described below:
To run the delay measurement as a continuous measurement or sweep, Burst must be
selected as the generator function with Low Level = 0 (no offset) so that arming can be
performed by the burst pause.
●
The measurement can be made using "one or two channels". If only one signal is
to be observed, the unused channel should be disabled in the Analyzer Config
panel, and Trace B should be disabled in the Waveform Config panel.
Analysis in the Time Domain