Concepts and features
R&S
®
ZND
141
User Manual 1173.9557.02 ─ 61
1.00000000009 -2.375070438098596e-01 -4.533104459856211e-01
1.01000000009 -3.132740349817996e-01 -5.874596585157938e-01
1.02000000009 -3.062444919836442e-01 -4.587379501906624e-01
Conditions for Touchstone file export
●
One-port Touchstone files with data from a single trace
Typically, Touchstone files contain a complete set of S-parameter traces of an n-
port network. The only exceptions are
s1p
files created from arbitrary S-parameter
traces using the "s1p Active Trace" export function in the
or the
.
●
Touchstone files containing S-matrices
–
For a one-port Touchstone file, the reflection coefficient for the specified port
(S
ii
for port i) must be measured. If a full one-port (Refl OSM) or a full n-port
(TOSM, ...) calibration is available for the specified port, it is possible to export
the data even when the trace is not displayed.
–
For a multiport Touchstone file
*.s<n>p
, either a full multiport system error
correction or a complete set of n
2
S-parameter traces must be available.
If the port configuration contains balanced ports, the exported Touchstone file
contains the converted single-ended S-parameters unless you enable "Bal-
anced Params" during export.
–
Export of balanced (symmetric) S-parameters must be enabled. If you want to
export balanced S-parameters, make sure that all these parameters are mea-
sured, and that for each involved balanced port both physical ports are part of
the export.
This type of export can be initiated from the GUI by using the "s<n>p Port ..." or
"snp Free Config. ..." functions of the
or by the remote command
For a unidirectional R&S
ZND (see
ZND: unidirectional vs. bidir-
on page 80) the S-parameters S
i2
cannot be measured and hence
an export to
*.s2p
file is not available. However, you can
import
S-parameter traces
from arbitrary
*.snp
files.
Renormalization of S-parameters
Renormalization means that the S-parameters at connector impedances are converted
to S-parameters at certain target impedances.
During Touchstone export, the S-parameters can be renormalized in two ways:
●
Common target impedance
The
<reference resistance>
impedance and the data is renormalized to the common target impedance, regard-
less of the reference impedances of the involved ports.
If the impedances of all involved ports are identical, the analyzer sets the
<reference resistance>
to the real part of this impedance.
Otherwise it sets it to 50 (Ω).
●
Port-specific
Operations on traces
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