Concepts and features
R&S
®
ZND
207
User Manual 1173.9557.02 ─ 61
The properties of the time gates are analogous to the properties of the frequency
domain windows. The following table gives an overview:
Table 4-18: Properties of time gates
Window
Side lobe
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 accu-
racy are low
Steep Edges
(Hamming)
43 dB
0.019 dB
Good compromise between edge steepness
and side lobe suppression
Normal Gate
(Hann)
32 dB
0.032 dB
Good compromise between edge steepness
and side lobe suppression
Maximum Flat-
ness (Bohman)
46 dB
0 dB
Maximum attenuation of responses outside the
gate span
Arbitrary Gate
Shape (Dolph-
Chebychev)
User defined
between 10 dB
and 120 dB
0.071 dB
Adjustment to individual needs; tradeoff
between side lobe suppression and edge
steepness
Time-gated frequency domain trace
The trace in the frequency domain depends on the state of the "Time Gate":
●
If the gate is disabled, the frequency domain (FD) trace corresponds to the mea-
sured sweep results before the time-domain transformation.
●
If the gate is enabled, the displayed frequency domain trace is calculated from the
time domain (TD) trace which is gated and transformed back into the frequency
domain.
The analyzer uses fixed "No Profiling (Rectangle)" window settings to transform the
measured trace into time domain. The TD trace is gated using the selected time gate.
The gated trace is transformed back into frequency domain using a "No Profiling (Rect-
angle)" window.
The shape, width and position of the time gate affect the gated frequency domain
trace. The window type selection in the "Define Transform" dialog is ignored. The
selected window is used again when the TD trace is displayed ("Time Domain: On").
Optional extensions and accessories
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