R&S ZNB Series User Manual page 578

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R&S ZNB/ZNBT
This mode is usually faster than "Chopped" mode.
●
In "Block Alternated" mode, you can split the sweep range into several blocks of
sweep points. The measurement then proceeds block per block, using the "Alterna-
ted" driving mode for each block.
●
In "Chopped" mode, the analyzer completes the necessary sequence of partial
measurements at each sweep point and obtains the result (measurement point)
before proceeding to the next sweep point. A trace is obtained from the beginning
of the sweep.
The "Driving Mode" setting is also used during a system error correction. For channels
which require a single partial measurement only, the driving mode settings are equiva-
lent. See also
Remote command:
[SENSe<Ch>:]COUPle
Number of Alternated Blocks
Defines the number of blocks for the "Block Alternated"
If "Number of Alternated Blocks" is set to 1, "Block Alternated" is equivalent to "Alterna-
ted" mode. If it is set to the
"Chopped" mode. By selecting a suitable
sweep duration.
Note:
●
If the number of sweep points is not divisible by the number of blocks, the first
block is extended by the excessive number sweep points.
●
For segmented sweeps, the "Block Alternated"/"Number of Alternated Blocks" logic
is applied to the individual sweep segments.
Remote command:
[SENSe<Ch>:]COUPle BLOCk, <Number of Alternated Blocks>
Image Suppr.
The "Image Suppr." settings define whether the analyzer measures with a local oscilla-
tor frequency LO below or above the RF input frequency. This feature can be used to
eliminate known spurious components in the input signal that can distort the measure-
ment, especially in the low frequency range.
●
In "Auto" mode, the analyzer auto-selects the LO frequency, depending on the
receiver (RF) frequency and the test port. This mode systematically avoids known
spurious signals if no frequency conversion occurs in the test setup.
●
"LO < RF" means that the LO frequency is always below the measured RF fre-
quency. This mode is appropriate for avoiding single, known spurious signals.
●
"LO > RF" means that the LO frequency is always above the measured RF fre-
quency. This mode is appropriate for avoiding single, known spurious signals.
Tip: In the presence of several spurious signals, setting the "Image Suppr." parameter
globally can be insufficient. To improve the result, perform a segmented frequency
sweep and assign independent LO frequencies to the individual sweep segments.
Application example
User Manual 1173.9163.02 ─ 62
Chapter 4.1.4.1, "Partial measurements and driving
number of sweep
Channel Config softtool
Driving Mode.
points, "Block Alternated" is equivalent to
number of blocks, you can minimize the total
GUI reference
mode", on page 91.
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