Concepts and features
R&S
®
ZNB/ZNBT
92
User Manual 1173.9163.02 ─ 62
Use the "Alternated" mode to increase the accuracy of measurements on DUTs with
long level settling times (e.g. quartzes, SAW filters). To measure DUTs with short set-
tling times and obtain a trace from the beginning of the sweep, use "Chopped" mode.
In "Auto" mode, the analyzer optimizes the display update: Fast sweeps are performed
in "Alternated" mode, slower sweeps in "Chopped" mode.
As an alternative to activating the "Alternated" mode, it is possible to insert a measure-
ment delay before each partial measurement and thus improve the accuracy.
See Channel – [Sweep] > "Sweep Params" > "Meas Delay".
However, the delay slows down the measurement.
Relation to trigger settings
In triggered measurements, "Alternated" and "Block Alternated" have no effect, if the
triggered measurement sequence is identical to a single sweep point. The following
table shows how the analyzer performs a sweep comprising
m
sweep points, assuming
that each of them requires
n
partial measurements.
Triggered Meas.
Sequence
"Alternated" mode
"Chopped" mode
Sweep
Trigger event starts
n
partial sweeps over
all sweep points.
Trigger event starts
m
complete
measurements at consecutive sweep
points.
Sweep Segment
Trigger event starts
n
partial sweeps over
the next segment.
Trigger event starts complete mea-
surements at all consecutive sweep
points in the segment.
Point
All partial measurements of each sweep
point are carried out one after another.
All partial measurements of each
sweep point are carried out one after
another.
Partial Measurement
Each partial measurement is carried out
for all sweep points.
All partial measurements of each
sweep point are carried out one after
another
Block Alternated driving mode
The "Block Alternated" driving mode that was introduced in firmware version 3.30,
allows you to split the sweep range into several (~ equally sized) blocks of sweep
points. The measurement proceeds block per block, using the "Alternated" driving
mode for each block.
If two or more partial measurements are required, you can minimize the overall sweep
duration by selecting a suitable number of blocks.
4.1.4.2
Pipelining of measurement data
In the legacy implementation of the alternated driving mode, the next sweep begins
when all trace data from the previous sweep has been processed.
Basic concepts
