Trace Menu    R&S
®
ZVA/ZVB/ZVT 
1145.1084.12 4.70  E-6 
Define Time Gate 
The Define Time Gate defines the properties of the time gate used to eliminate unwanted 
responses that appear on the time domain transform. 
• Start and Stop or Center and Span define the size of the time gate.  
• The filter Type defines what occurs to the data in the specific time region. A Band Pass filter 
passes all information in the specified time region and rejects everything else. A Notch  filter 
rejects all information in the specified time region and passes everything else.  
• The  Gate Shape panel visualizes how the time gate will affect a constant function after 
transformation back into the frequency domain. The selected window is applied to the active 
trace. The two red vertical lines represent the Start and Stop values defining the size of the time 
gate.  
• If an Arbitrary Gate Shape (Dolph-Chebychev) window is selected, the Arbitrary Sidelobe Level 
can be set below the Gate Shape diagrams.  
Use the paste marker list for convenient entry of Start and Stop values.  
•
Comparison of time gates  
The properties of the time gates are analogous to the properties of the frequency domain windows. The 
following table gives an overview:  
Window Sidelobe suppression Passband 
ripple 
Best for... 
Steepest Edges 
(Rectangle)  
13 dB  0.547 dB  Eliminate small distortions in the vicinity of the 
useful signal, if demands on amplitude accuracy 
are low 
Steep Edges 
(Hamming) 
43 dB  0.019 dB  Good compromise between edge steepness and 
sidelobe suppression  
Normal Gate (Hann)  32 dB  0.032 dB  Good compromise between edge steepness and 
sidelobe suppression