[ibis-interconn] I have a couple questions about the Touchstone 2 Network Data Format

From: Walter Katz <wkatz@xxxxxxxxxxxxx>
To: 'IBIS-Interconnect' <ibis-interconn@xxxxxxxxxxxxx>
Date: Tue, 18 Jan 2022 19:38:47 +0000

All,

The first question is about splitting the two values in an Sij between two
rows. The second is an editorial comment about network data fromat.

On page 5 Touchstone 2 specification the specification states:

Touchstone data files consist of an "option line" followed by network
parameters taken at specific
frequencies. The option line specifies (among other things) the kind of n-port
parameters the file contains
(S-parameter, Z-parameter, etc.) and the format of the network data values
(magnitude-phase, realimaginary,
etc.). Data is arranged into groups of n-port parameters preceded by the
frequency at which the
data was taken or derived. For each frequency, data for a 1-port or 2-port
network is contained on a single
data line while data for 3-port and above networks is arranged in a matrix
row-wise order. The Touchstone
format supports matrices of unlimited size.

On page 12 of the Touchstone 2 specification it states:

Following the option line (Version 1.0 files) or [Network Data] keyword
(Version 2.0 files) are the network
parameters (S-parameter, Z-parameter, etc.) of the type specified by the option
line. Groups of n-port
parameters are preceded by the frequency value for which the data was obtained,
and the n-port parameters
themselves are formatted as pairs of values (magnitude-angle, dB-angle or
real-imaginary).

On page 13 of the Touchstone 2 specification it states:

Rules for Version 2.0:
In Version 2.0 files, the data associated with any one frequency may be split
across any number of lines or
may be placed on a single line of arbitrary length. Network data in a Version
2.0 file is parsed using the
[Number of Ports] keyword and argument and the [Matrix Format] keyword and
argument. For a Full
matrix, a new frequency point is expected every 2n2 + 1 values, where n is the
number of ports, regardless
of intervening line termination sequences or characters. For a Lower or Upper
matrix, a new frequency
point is expected every n2 + n + 1 values.

On page 14 of the Touchstone 2 specification it states:

The following probably should be changed.
In the above example, the value of S11 at a frequency of 2 MHz is given in
magnitude-angle format. The
reference impedance is 50 ohms.
To
In the above example, the values of S11 at a frequency of 2 MHz is two values
in magnitude-angle format. The
reference impedance is 50 ohms.

On page 17 of the Touchstone 2 specification it states:
No example shows Touchstone 2 examples where the Nij is split between two lines.

Rules for Version 2.0 Files:
Version 2.0 files may continue data on the same line or across multiple lines.
As usual, each group of
network data pairs is preceded by the frequency value at which this data was
taken.
For files using a [Matrix Format] of Lower or Upper, data is still represented
in a row-wise format, as
shown for 3- and 4-port networks above.
These rules are illustrated by showing the format for a 6-port network:
6-port Full network format (single frequency point)
<frequency value> <N11> <N12> <N13> <N14> !row 1
<N15> <N16>
<N21> <N22> <N23> <N24> !row 2
<N25> <N26>
<N31> <N32> <N33> <N34> !row 3
<N35> <N36>
<N41> <N42> <N43> <N44> !row 4
<N45> <N46>
<N51> <N52> <N53> <N54> !row 5
<N55> <N56>
<N61> <N62> <N63> <N64> !row 6
<N65> <N66>

On page 18 of the Touchstone 2 specification it states:
Are the characters marked in red "typos" and should they be removed?

Example 15 (Version 1.0):
# frequency_unit Y MA R impedance
freq magY11 angY11 magY12 angY12 magY13 angY13 magY14 angY14 ! 1st row
magY15 angY15 magY16 angY16 magY17 angY17 magY18 angY18
magY19 angY19 magY1,10 angY1,10
magY21 angY21 magY22 angY22 magY23 angY23 magY24 angY24 ! 2nd row
magY25 angY25 magY26 angY26 magY27 angY27 magY28 angY28
magY29 angY29 magY2,10 angY2,10
magY31 angY31 magY32 angY32 magY33 angY33 magY34 angY34 ! 3rd row
magY35 angY35 magY36 angY36 magY37 angY37 magY38 angY38
magY39 angY39 magY3,10 angY3,10
magY41 angY41 magY42 angY42 magY43 angY43 magY44 angY44

Walter

Walter Katz
Work 508.647-7633
Cell 720.417-3762
[Description: Description: Visit MathWorks.com]

[ibis-interconn] I have a couple questions about the Touchstone 2 Network Data Format

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