eldo_user

Working with S, Y, Z Parameters
Touchstone Data File Format
Touchstone Data File Format
Input or output for: Eldo and Eldo RF; output generated by the .FFILE command
Eldo fully supports Touchstone® versions v1 and v2 formats for reading and writing. When
reading, the format is automatically detected.
Note
See the .FFILE command in the Eldo Reference Manual.
Format
The Touchstone data format file is an ASCII text file in which data appears line by line: N lines
for each data point of N ports. The data points are stored in increasing order of frequency.
The first of the N lines consist of a frequency value and N pairs of values for S, Y, Z, G, H, T or
A parameters. The (N-1) following lines contain N pairs of values. Values are separated by one
or more spaces or tabulations.
Tip
Touchstone data format files follow general syntax rules. The standard is available from the
EDA Industry Working Groups website:
Touchstone version 1:
http://www.eda.org/pub/ibis/connector/touchstone_spec11.pdf
Touchstone version 2:
http://www.eda.org/pub/ibis/touchstone_ver2.0/touchstone_ver2_0.pdf
• Comment lines begin with an exclamation mark (!).
• The first uncommented line in the Touchstone data file must be an option specification
line that begins with the pound sign (#) followed by a space. The option line is formatted
as follows:
# [Hz|kHz|MHz|GHz] [S|Y|Z|G|H|T|A] [RI|MA|DB] [R Val|R1 Val1 ... Rn
Valn]
Parameters
• [Hz|kHz|MHz|GHz]
Frequency Unit (Hz, kHz, MHz, GHz). Default value is Hz.
• [S|Y|Z|G|H|T|A]
Parameter type (S, Y, Z, G, H, T, A). Default value is S.
• [RI|MA|DB]
Data format (MA, DB, RI). Default value is RI. MA means Magnitude-angle in Volts, and
phase in degrees. DB means Magnitude in dB, and phase in degrees. RI means Real and
Imaginary parts.
Eldo® User's Manual, 15.3 705