Few can resist freebies. Whether you're here purely out of curiosity, or seeking to fulfull an urgent need, you might find just what you need. Essentially, this is a collection of utilities originally developed for specific jobs because there was no existing tool available, or because the alternative was unjustifiably expensive for the task at hand. Anything you find here is free because it comes without any guarantee of fit-for-purpose, or support, and is provided only as an enticement.
Nothing is knowingly listed here that you can get elsewhere.
s2p to s3p converter
Most network analysers have only two measurement ports, which means that if you have a 3-port network like a balun transformer, directional coupler, SAW filter, circulator etc, you can only make a series of 2-port measurements. Circuit simulators commonly accommodate n-port networks by importation of industry-standard snp (Touchstone®) format files.
For reasons lost in the distant past, the format of s3p (and higher) Touchstone® files can only be described as damned awkward. It is possible to take 3 s2p files and manually manipulate them into an s3p file, but since network analyser-generated files usually have 201, 401 or more frequencies, the likelihood of serious error or unhealthy frustration in manipulating 4 such files is more than 90%, I'd say. s2p to s4p conversion requires 6 input files ([n x (n-1)]/2), and so on.
The utility is provided as an Excel workbook, (a) since this is how it was originally written, and (b) because it gives the user the oportunity to easily edit the output file after conversion to add comments etc. (Comment lines in Touchstone® files must begin with the "!" character and are normally ignored regardless of where they appear in the file.)
If you need s4p or higher files, you can either try to modify the macros yourself, or send us an email with details of what you are trying to do, and we'll try to produce an extended version when time permits. If your need is more urgent than that, let us know anyway - it may be cost-effective to commision it.
