Concepts and features
R&S
®
ZNA
151
User Manual 1178.6462.02 ─ 20
●
Blank lines are permitted.
Option line
Each Touchstone file must contain an option line with the following structure:
# <frequency unit> <parameter> <data format> R <reference
resistance>
●
#
indicates the beginning of the option line
●
<frequency unit>
can be either
Hz
,
kHz
,
MHz
or
GHz
. Default is
GHz
.
The R&S
ZNA always uses
HZ
for exported data.
●
<parameter>
specifies what kind of network parameter data is contained in the
file. Default is
S
for S-parameters, which is the only parameter type the R&S
ZNA
supports.
●
<data format>
specifies how the complex network parameter data are format-
ted. Possible values are
RI
for "Real-Imag",
MA
for "Lin Mag-Phase", and
DB
for
"dB Mag-Phase". Default is
MA
.
According to the Touchstone file standards, dB Mag = 20 × log
10
Mag, and the
phase is always represented in degrees.
During data export, the analyzer allows you to select the suitable
<data
format>
.
●
<reference resistance>
specifies the impedance system underlying the net-
work data, given as a real, positive resistance. Its value is given in Ω (default 50).
During export, if the impedances of all involved ports are identical, the analyzer
sets the
<reference resistance>
to the real part of this impedance. Other-
wise it sets it to 50.
With the exception of the opening
#
symbol and the value following
R
, option line
parameters can appear in any order. If a parameter is missing, the default value is
assumed.
Comments
Comments can be used for any kind of documentation purpose, e.g. to describe the
network parameter data and how they were generated.
Syntactically, comments are preceded by an exclamation mark and terminated by a
line termination sequence (see
anywhere in the file, either on a separate line, or after the parsed content of a line. Any
number of comment lines can be inserted.
The content of the comments is not standardized in any way. The following sections
describe the comments the R&S
ZNA inserts into a Touchstone file during export.
During import, the R&S
ZNA ignores all comments.
VNA identification
These comment lines identify the VNA that was used to generate the file.
Operations on traces
