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R&S ZVL
GUI Reference
Trace Menu
Operating Manual 1303.6580.32-06
144
•
The radio buttons in the
Type
panel select a band pass or low pass transform. To calculate a low
pass transform the sweep points must be on a harmonic grid (otherwise the analyzer will only be
able to calculate an approximate result and generate a warning).
Low Pass Settings...
opens a
dialog to establish or change a harmonic grid (not available for memory traces).
•
The
Impulse
panel shows the impulse response of a constant trace over a finite sweep range (i.e.
a rectangular function) that was filtered in the frequency domain using different windows. The
selected window is applied to the active trace. The analyzer always uses a
No Profiling
(Rectangle)
window to calculate the time-gated frequency domain trace, see background
information is section
Frequency Domain
.
•
If an
Arbitrary Sidelobes (Dolph-Chebychev)
window is selected, the
Arbitrary Sidelobe Level
(sidelobe suppression) can be set below the
Impulse Response
diagrams.
For a comparison of the different transformation types and windows and for application examples please
also refer to the application note 1EZ44_OE which is posted on the R&S internet.
The frequency domain window is used to filter the trace prior to the time domain transformation. An
independent Time Gate can be used after the transformation in order to eliminate unwanted
responses.
Remote control:
CALCulate<Chn>:TRANsform:TIME[:TYPE]
CALCulate<Chn>:TRANsform:TIME:STIMulus
CALCulate<Chn>:TRANsform:TIME:WINDow
CALCulate<Chn>:TRANsform:TIME:DCHebyshev
Band Pass and Low Pass Mode
The analyzer provides two essentially different types of time domain transforms:
•
Band pass mode : The time domain transform is based on the measurement results obtained in
the sweep range between any set of positive start and stop values. The sweep points must be
equidistant. No assumption is made about the measurement point at zero frequency (DC value).
The time domain result is complex with a generally undetermined phase depending on the delay
of the signal.
•
Low pass mode : The measurement results are continued towards f = 0 (DC value) and mirrored
at the frequency origin so that the effective sweep range (and thus the response resolution) is
more than doubled. Together with the DC value, the condition of equidistant sweep points implies