Concepts and Features
R&S
®
ZNB/ZNBT
135
User Manual 1173.9163.02 ─ 38
4.4.2.1
Touchstone Files
Touchstone files contain a header, a comment section, and the actual trace data:
# HZ S RI R 50.00
! Rohde & Schwarz Vector Network Analyzer
! Rohde-Schwarz,ZNB8-4Port,1311601044100005,1.93.1.42
! Created: UTC 9/17/2013, 9:13:56 AM
! freq[Hz] re:S11 im:S11
1.000000000000000E5 -4.897128641605377E-1 3.767784312367439E-2
4.259950000000000E7 -5.450598597526550E-1 3.608805686235428E-2
...
#
indicates the beginning of the header line (required at the top of file), which consists
of the following data elements:
●
<Frequency unit>:
HZ / KHZ / MHZ / GHZ
allowed for imported files; the ana-
lyzer always uses
HZ
for exported data.
●
<Data file type>: at present only
S
for S-parameter files is supported
●
<Data format>: RI for Re/Im, MA for linear Mag-Phase, DB for Mag-Phase in deci-
bels; the data format for export files can be selected in the Export Data dialog.
●
<Reference resistance>: specifies the impedance system underlying the trace
data, given as a real, positive resistance (default 50 Ω)
Comment lines start with the exclamation mark (!) and may contain any text used for
documentation of the trace data file. Any number of comment lines may be inserted
before or after the header line.
The following information is displayed in the comments section:
●
VNA identification (comment line 2 in above example)
●
timestamp (comment line 3)
●
port-specific renormalization information (comment lines 4ff, if applied; see
ple "Renormalization comments"
●
headings for included data tables (comment lines right above the data tables, start-
ing with
! freq
)
The trace data section corresponds to a set of single-ended S-parameters. It depends
on the number of ports and the data format. For real and imaginary values (<Data for-
mat> =
RI
) the trace data for each stimulus frequency is arranged as indicated in the
lowermost comment lines during export:
1-port files (*.s1p)
! freq[Hz] re:S11 im:S11
S
11
can be replaced by an any S-parameter, so the
*.s1p
format is suitable for export-
ing an arbitrary data trace representing an S-parameter.
2-port files (*.s2p)
! freq[Hz] re:S11 im:S11 re:S21 im:S21 re:S12 im:S12 re:S22 im:S22
(all values arranged in 1 line)
Operations on Traces