Concepts and Features
R&S
®
ZNC
65
User Manual 1173.9557.02 ─ 13
3.4.2.1
Touchstone Files
All Touchstone files contain a header, a comment section, and the actual trace data:
#
HZ
S
RI
R
50.0000
! Rohde & Schwarz ZNC
! Measurement: S11
! 2003-07-07
!
60297750.000000
0.498113
-0.054290
80297000.000000
0.504888
-0.081229
The header consists of the following data elements:
●
# specifies beginning of header line (required at top of file).
●
<Frequency unit>: HZ / KHZ / MHZ / GHZ allowed for imported files. The analyzer
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 lin. Mag-Phase, DB for dB Mag-Phase. The data
format for export files can be selected in the Export Data dialog.
●
<Normalizing impedance>: Impedance system in which the data was defined. The
analyzer uses 50.0000 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 trace data section corresponds to a set of single-ended S-parameters. It depends
on the number of ports <n> and the data format.
For real and imaginary values (data format = Real-Imag) the trace data for each stimulus
frequency is arranged as follows:
●
1-port files (
*.s1p
)
Freq
Re(S
11
)
Im(S
11
)
S
11
can be replaced by an any S-parameter, so the
*.s1p
format is suitable for
exporting an arbitrary data trace representing an S-parameter.
●
2-port files (
*.s2p
)
Freq
Re(S
11
)
Im(S
11
)
Re(S
21
)
Im(S
21
)
Re(S
12
)
Im(S
12
)
Re(S
22
)
Im(S
22
)
(all values arranged in 1 line)
The stimulus frequencies are arranged in ascending order. If a "lin. Mag-Phase (MA)" or
"dB Mag-Phase (DB)" data format is selected the real and imaginary S-parameter values
Re(S
ij
), Im(S
ij
) are replaced by lin Mag(S
ij
), phase(S
ij
) or dB Mag(S
ij
), phase(S
ij
), respec-
tively.
According to Touchstone file specifications, no more than four pairs of network data are
allowed per data line. The entries in the data lines are separated by white space, and a
Operations on Traces
