GUI reference
R&S
®
ZNA
401
User Manual 1178.6462.02 ─ 20
*) The operand "StimVal" can be used for all sweep types. Please note that – as with
all user math operands – only the numerical value without unit is processed in the user
math formula.
●
In frequency sweeps "StimVal" provides the stimulus frequency in Hz.
●
In power sweeps, "StimVal" provides the voltage in V that results from the source
power in dBm. To obtain the correct source power in dBm (for "dB Mag" trace for-
mat),
must be enabled. Note that, due to the conversion
into a dBm value, the source power depends on the reference impedance of the
port associated with the measured wave quantity, to be set in the "Balanced Ports"
dialog.
●
In time sweeps, "StimVal" is the stimulus time in s.
●
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.
●
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.
●
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
, the "Show as" control element specifies whether
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>
2
/Re(Z
0
)). Results in "dB Mag" format are calculated according to <P>
log
= 10 * log
(<P>/1mW).
●
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>
log
= 20 * log (<W>).
Traces softtool
