From: roucaries bastien <roucaries.bastien@gm...>  20080716 13:06:13

On Wed, Jul 16, 2008 at 2:41 PM, Christian Friesicke <christian.friesicke@...> wrote: > 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 have planned a full rewriteof this stuff but it is quite difficult due to complex impedance issue. A good fundation paper is "Power Waves and the Scattering Matrix" Kurokawa, K. , IEEE MTT, 1965, see eq 32. > 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. One of my collegueat uni have just done a phd thesis about this thematic see http://ethesis.inptoulouse.fr/archive/00000462/01/boussalem.pdf (in french). It is based on the hill equation. Could snd you privatly his email Regards bastien > >  > This SF.Net email is sponsored by the Moblin Your Move Developer's challenge > Build the coolest Linux based applications with Moblin SDK & win great prizes > Grand prize is a trip for two to an Open Source event anywhere in the world > http://moblincontest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > Qucsdevel mailing list > Qucsdevel@... > https://lists.sourceforge.net/lists/listinfo/qucsdevel > 