Operating Manual 1303.6580.32-06
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
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
*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
Due to the properties of the Chirp z-transformation the trace is periodic in time and repeats after an
unambiguous range of Qt = 1/Qf, where Qf 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.
CALCulate<Chn>:TRANsform:TIME:XAXis TIME | DISTance
Opens a submenu to change the stimulus axis in the frequency domain. The settings are identical with the
Channel – Stimulus settings.
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.