Rohde & Schwarz 1145.1010.04/05/06, Operating Manual

Page: 225 / 813

R&S
®
ZVA/ZVB/ZVT Trace Menu
1145.1084.12 4.63 E-6
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.
•
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).
Low Pass Settings... opens a dialog to
establish or change a harmonic grid (not available for memory traces).
•
The Impulse Response 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.
•
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<Ch/Tr>:TRANsform:TIME[:TYPE]
CALCulate<Ch/Tr>:TRANsform:TIME:STIMulus
CALCulate<Ch/Tr>:TRANsform:TIME:WINDow
CALCulate<Ch/Tr>: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