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Basic operation
R&S
®
ZNA67EXT
46
Getting Started 1179.6295.02 ─ 02
c) "Leveling Table (Global)"
Perform leveling if you want the power levels at the waveguide port to be
constant over frequency. Also perform leveling if you want to have fre-
quency-independent, variable, known absolute power levels at the wave-
guide port. The latter is necessary for power sweeps, but also for auto-
matic level control (ALC).
Use ALC for measurements that require precise power levels at the 1
mm
port, in particular for measuring non-linear characteristics of a DUT (com-
pression, intermodulation, spectrum...). For details on ALC, see the
R&S
ZNA help system or user manual.
Based on an existing reference receiver calibration, the leveling procedure
records the output power on a two-dimensional power/frequency grid. The
VNA firmware then uses Interpolation to determine the appropriate RF IN
level for the desired output level at a given frequency.
d) "Source Flatness"
Based on an existing reference receiver calibration, the R&S
ZNA varies
the frequency and adjusts its source power so that the reference receiver
readings correspond to the desired output power at the waveguide port of
the converter.
For operation with external test sets, make sure that the convergence fac-
tor is 0.3 or lower (Channel – [Cal] key > "Power Cal Settings" tab > "Con-
vergence").
If leveling data is available for a port, a source flatness calibration is not
necessary unless you want to achieve a higher precision at a particular fre-
quency. To get even higher precision within the whole frequency range,
use the automatic level control (ALC) feature of the R&S
ZNA. Note that
ALC at a converter port requires leveling data for this port. Refer to the
R&S
ZNA help system or user manual for details.
Scalar power calibration and leveling (optional)