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R&S ZVL
GUI Reference
Trace Menu
Operating Manual 1303.6580.32-06
143
•
Start
is the lowest displayed time and corresponds to the left edge of the Cartesian diagram.
•
Stop
is the highest displayed time and corresponds to the right edge of the Cartesian diagram.
•
Center
corresponds to the center of the Cartesian diagram, i.e. (Start + Stop)/2.
•
Span
corresponds to the diagram width, i.e. (Stop Start).
•
Time
and
Distance
switch over between the x-axis scaling in time units or distance units.
Use the paste marker list for convenient entry of
Start
and
Stop
values.
Distance units for transmission and reflection parameters
The interpretation of time and distance depends on the measurement type. For reflection measurements,
the time axis represents the propagation time of a signal from the source to the DUT and back. For
transmission measurement, it represents the propagation time from the source through the device to the
receiver. The
Distance
calculation is consistent with this interpretation:
•
For reflection measurements (S-parameters S
ii
or ratios with equal port indices) the distance
between the source and the DUT is half the propagation time multiplied by the velocity of light in
the vacuum times the velocity factor of the receiving port defined in the
Channel Offset
menu
(Distance = 1/2 * Time * c
0
* Velocity Factor)
. The factor 1/2 accounts for the return trip from the
DUT to the receiver.
•
For transmission measurements, the distance is calculated as the propagation time times the
velocity of light in the vacuum times the velocity factor of the receiving port defined in the
Channel
Offset
menu
(Distance = Time * c
0
* Velocity Factor)
.
Due to the properties of the Chirp z-transformation the trace is periodic in time and repeats after an
unambiguous range of
Q
t = 1/
Q
f, where
Q
f is the spacing between two consecutive frequency points. To
extend the unambiguous range, either reduce the sweep span (
Channel
–
Center / Span
) or increase the
number of sweep points.
Remote control:
CALCulate<Chn>:TRANsform:TIME:STARt
CALCulate<Chn>:TRANsform:TIME:STOP
CALCulate<Chn>:TRANsform:TIME:CENTer
CALCulate<Chn>:TRANsform:TIME:SPAN
CALCulate<Chn>:TRANsform:TIME:XAXis TIME | DISTance
Stimulus Frequency
Opens a submenu to change the stimulus axis in the frequency domain. The settings are identical with the
Channel
–
Stimulus
settings.
Remote control:
[SENSe<Ch>:]FREQuency:STARt
[SENSe<Ch>:]FREQuency:STOP
[SENSe<Ch>:]FREQuency:CENTer
[SENSe<Ch>:]FREQuency:SPAN
Define Transform
The
Define Transform
dialog selects the transformation type and the frequency domain window which is
applied to the trace in order to optimize its time domain response.