From: Christian Friesicke <christian.friesicke@tu...>  20080716 12:41:51

Hey guys, the devellist is probably not the best forum for a request like this but I have one rather simple question about the Qucs Technical Paper published at http://qucs.sourceforge.net/tech/technical.html In the Mathematical Background you give a formula for renormalizing Sparameters to a new set of port impedances (formula 15.1). Can you give me a reference (e.g., to an IEEE paper) where this formula comes from? I know of one reference, JC Tippet, IEEE Trans. MTT, Vol. 30, No. 5, May 1982 (see Appendix V, formula (7)) which basically contains something very similar to formula 15.1 (using a different nomenclature). Comparing Tippet's formulation with yours, I am wondering where the square root in your [A]matrix is coming from? According to Tippet, we would have [A]=[E][R] (using your nomenclature) but that does not agree with your definition of [A]. I would appreciate any help. Regards, Christian Friesicke PS: About me  I am currently doing my diploma thesis at Hamburg University of Technology (TUHH). My research is about nonuniform transmission lines, and I have tinkered a lot with portions of code from Transcalc (microstrip, coupled microstrip), which I ported to Matlab. I have also done some improvements to the stability of the code (analysis and synthesis). Transcalc seems dead :( but luckily it is kept alive in qucstranscalc. I decided to read the list here because I wanted to feed back some of my improvements and ideas when time permits. 