R&S ZNB Series User Manual page 327

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R&S ZNB/ZNBT
Application: Transmission measurements, especially with the purpose of investigating
deviations from linear phase response and phase distortions. To obtain the delay, a fre-
quency sweep must be active.
Tip: The cables between the analyzer test ports and the DUT introduce an unwanted
delay, which often can be assumed to be constant. Use the Zero Delay at Marker func-
tion, define a numeric length "Offset" or use the "Auto Length" function to compensate
for this effect in the measurement results. To compensate for a frequency-dependent
delay in the test setup, a system error correction is required.
Note: The delay for reflection factors corresponds to the transmission time in forward
and reverse direction; see
on page 204.
Remote command:
CALCulate<Chn>:FORMat
Aperture Points
Defines an aperture Δf for the (group) "Delay" calculation. The value is entered as
number of sweep steps (= number of sweep points - 1).
For background information, see
Properties: The delay at each sweep point is computed as:
where the aperture Δf is a finite frequency interval around the sweep point f
analyzer measures the corresponding phase change ΔΦ, which is calculated via a lin-
ear regression algorithm over the frequency points of the aperture.
Application: The aperture must be adjusted to the conditions of the measurement. A
small aperture increases the noise in the group delay; a large aperture tends to mini-
mize the effects of noise and phase uncertainty, but at the expense of frequency reso-
lution. Phase distortions (i.e. deviations from linear phase) which are narrower in fre-
quency than the aperture tend to be smeared over and cannot be measured.
Remote command:
CALCulate<Chn>:GDAPerture:SCOunt
Dflt Marker Frmt
Defines the default marker format of the active trace. "Default" means formatted
according to the selected trace format.
New markers are formatted with the trace's "Dflt Marker Frmt"; existing markers are
reformatted if (and only if) their
For background information on marker formats, see
Remote command:
CALCulate<Chn>:MARKer:DEFault:FORMat
User Manual 1173.9163.02 ─ 62
"Length and delay measurement, related settings"
GDELay
Chapter 4.3.8, "Group
Marker Format is set to (Trace) "Default".
GUI reference
Format softtool
delay", on page 143.
"Marker format" on page 107.
and the
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