R&S ZNB Series User Manual page 347

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R&S ZNB/ZNBT
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In time sweeps, "StimVal" is the stimulus time in s.
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In CW mode sweeps, "StimVal" is the number of the point.
Remote command:
CALCulate<Chn>:MATH[:EXPRession]:SDEFine
CALCulate<Chn>:MATH:FORMatted[:EXPRession]:SDEFine
Result is Wave Quantity
"Result is Wave Quantity" controls the conversion and formatting of the mathematic
expression.
This switch is available for unformatted trace data (Complex Data) only.
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If "Result is Wave Quantity" is enabled, the analyzer assumes that the result of the
mathematical expression represents a voltage. Examples for voltage-type expres-
sions are all terms proportional to a wave quantity (e.g. 1.1*Data, if a wave quantity
is measured) or to a stimulus value of a power sweep.
If "Show as": "Power" is selected in the "More Wave Quantities" dialog, the result is
converted into a linear power before the selected trace format is applied. Otherwise
no conversion is performed, and "dB Mag" results are referenced to 1 μV.
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If "Result is Wave Quantity" is disabled the analyzer assumes that the result of the
mathematical expression is dimensionless. Examples for dimensionless expres-
sions are all terms proportional to ratios of wave quantities, e.g. Data / Mem2[Trc1].
The selected trace format is applied without previous conversion.
"Result is Wave Quantity" acts on the result of the mathematical expression only. Wave
quantities and power sweep stimulus values always enter into the expression as vol-
tages.
Effect of "Result is Wave Quantity"
In the
wave quantities are displayed as voltages or equivalent powers, using the port impe-
dances for a conversion between the two representations. "Result is Wave Quantity" is
relevant for mathematical traces displayed in units of dBm ("Show as": "Power" and
trace format "dB Mag"):
If "Result is Wave Quantity" is on (checked), the mathematical trace values <W> are
interpreted as voltages and first converted into equivalent powers (<W> —> <P> =
<W>
(<P>/1mW).
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If "Result is Wave Quantity" is off, the mathematical trace values <W> are interpre-
ted as dimensionless quantities. Results in "dB Mag" format are calculated accord-
ing to <W>
Example:
A mathematical trace value amounts to 1 (real value); the port impedance is 50 Ω. If
"Result is Wave Quantity" is on, the analyzer assumes the trace value to be 1 V, which
is converted into a linear power of 20 mW, corresponding to approx. 13 dBm. With
"Result is Wave Quantity" off, the trace value 1 is directly converted into a logarithmic
power of 0 dBm.
Tip: See also example for CALCulate<Chn>:MATH:WUNit:STATe.
User Manual 1173.9163.02 ─ 62
More Wave Quantities
2
/Re(Z )). Results in "dB Mag" format are calculated according to <P>
0
= 20 * log (<W>).
log
dialog, the "Show as" control element specifies whether
GUI reference
Trace Config softtool
= 10 * log
log
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