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GUI Reference
R&S
®
ZNB/ZNBT
315
User Manual 1173.9163.02 ─ 53
Is the Current Grid Harmonic?
The area at the top of the "Low Pass Settings" dialog indicates whether the current fre-
quency grid is harmonic.
Remote command:
Set Harmonic Grid and Keep
The three buttons provide alternative algorithms for calculation of a harmonic grid,
based on the current sweep points.
●
Keep "Stop Frequency and Number of Points" calculates a harmonic grid based on
the current "Stop Frequency" (see
"Start Frequency / Stop Frequency / Center Fre-
on page 385) and the current number of sweep points
(see
on page 394). This algorithm can increase the frequency
) .
●
Keep "Frequency Gap and Number of Points" calculates a harmonic grid based on
the current "Stop Frequency" and the current frequency gap (i.e. the "Freq Step
Size").
●
Keep "Stop Frequency and Approximate Frequency Gap" calculates a harmonic
grid based on the current "Stop Frequency", increasing the "Number of Points" in
such a way that the frequency gap (i.e. the "Freq Step Size") remains approxi-
mately the same. This algorithm can increase the sweep time, due to the additional
sweep points introduced.
The three grids can be calculated repeatedly in any order; the analyzer always starts
from the original set of sweep points.
For more information, refer to
Chapter 5.7.2.4, "Harmonic Grid"
Remote command:
CALCulate<Chn>:TRANsform:TIME:LPASs
Automatic Harmonic Grid
If enabled (default) the frequency grid is automatically kept harmonic.
Remote command:
DC Value
The control elements in this section define the measurement result at zero frequency
and in the interpolation/extrapolation range between f = 0 and f = f
min
. They are
enabled after a harmonic grid has been established.
Defining the low frequency sweep points
After calculating a harmonic grid, the analyzer must determine the value of the mea-
sured quantity at grid points below the analyzer's minimum frequency f
min
.
The following figure shows a scenario where the harmonic grid was calculated with
fixed "Stop Frequency and Number of Points". The DC value and the values at the two
additional red points must be extrapolated or interpolated according to the values at
the measured sweep points (blue dots).
Trace Config Softtool