R&S ZNB Series User Manual page 513

®
R&S ZNB/ZNBT
Char. Imp.
The characteristic impedance or reference impedance ("Char. Imp.") Z
tors is a critical value that has an impact on various parameter conversions. Z
into:
●
The calculation of the S-parameters for the calibration standards associated with
the connector type, if they are derived from a circuit model (see
Kit Standards dialog"
●
The calculation of the (default) reference impedances for balanced ports (see
erence Impedance tab"
●
The calculation of impedance and admittance parameters (see
"Impedance
ters",
Remote command:
[SENSe<Ch>:]CORRection:CONNection
Line Type / Rel. Permittivity εr / Cutoff Freq. fc
"Line Type" describes the wave propagation mode (offset model) in the transmission
lines of the standards associated with the connector type.
●
If the calibration kit standards contain lines with transverse electric propagation
mode (TEM, e.g. coax cables), then the "Rel. Permittivity εr" of the dielectric can be
defined. The default permittivity is the value for air. TEM-type lines have no cutoff
frequency.
●
If the calibration kit standards contain waveguides, then the lowest frequency
where a wave propagation is possible ("Cutoff Freq. fc") can be defined. The
default cutoff frequency if 0 Hz (propagation at all frequencies). No relative permit-
tivity is needed for waveguides.
Note: The impedance for waveguides is frequency-dependent. If a waveguide line type
is selected, various dialogs indicate "varies" instead of a definite impedance value.
Impact of line type parameters
The line type parameters are used for the calculation of the S-parameters for the cali-
bration standards associated with the connector type, if they are derived from a circuit
model (see
●
For TEM-type lines, the relative permittivity ε
ZVR-type "Loss" (in units of dB/sqrt(GHz)) into a Keysight-type "Offset Loss" (in
units of GΩ/s) and vice versa (see
on page 518). The "Electrical Length" and "Delay" values in the
Kit Standards dialog
●
For waveguides, the low frequency cutoff frequency f
wave propagation is possible at frequencies below f
acquire calibration data, the analyzer checks the low frequency cutoff. If the start
frequency of the sweep range is below f
The offset model parameters are not used except in the context of calibration. The off-
set parameter definitions are based on independent ε
"Offset
Remote command:
[SENSe<Ch>:]CORRection:CONNection
User Manual 1173.9163.02 ─ 62
on page 518).
on page 292).
parameters",
on page 134).
"View / Modify Cal Kit Standards dialog"
are directly entered and therefore independent of ε
tab", on page 615.
on page 130 and Chapter 4.3.4, "Admittance parame-
is needed for the conversion of a
r
"View / Modify Cal Kit Standards dialog"
, an error message is generated.
c
GUI reference
Cal softtool
for the connec-
0
"View / Modify Cal
Chapter 4.3.3,
on page 518).
View / Modify Cal
is important because no
c
. If a standard is measured to
c
values; see Chapter 5.13.2,
r
enters
0
"Ref-
.
r
513