What I've seen is that "field solvers", which don't rely on closed-form solutions seem to be the state of the art.
Matt On 3/14/07, Dr Bruce Griffiths <[EMAIL PROTECTED]> wrote: > Matt Ettus wrote: > > I was just investigating this very issue. It seems that every program > > you use to compute these impedances comes up with different answers, > > sometimes wildly different. Anyone have a free program they trust > > with this sort of thing? > > > > Matt > > > > On 3/14/07, Dr Bruce Griffiths <[EMAIL PROTECTED]> wrote: > > > >> Tom Clark, K3IO wrote: > >> > >>> I just stumbled on an excellent tutorial on low-noise clocks -- > >>> National Semiconductors free downloadable "[1]Clock Conditioner > >>> Owner's Manual". This 88 page document is a 3.7 MB PDF. > >>> 73 de Tom, K3IO > >>> > >>> References > >>> > >>> 1. > >>> http://www.national.com/appinfo/interface/files/clk_conditioner_owners_manual.pdf > >>> _______________________________________________ > >>> time-nuts mailing list > >>> [email protected] > >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >>> > >>> > >>> > >> Tom > >> > >> Not bad except they give inaccurate formulae for stripline and > >> microstripline characteristic impedance. > >> Will these inaccurate formulae ever go away? > >> They've been around since the 1970's. > >> When with the trace widths and board thickness then in use the accuracy > >> wasn't too bad. > >> However they are not very useful for modern PCB design. > >> > >> Bruce > >> > >> _______________________________________________ > >> time-nuts mailing list > >> [email protected] > >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > >> > >> > > > > _______________________________________________ > > time-nuts mailing list > > [email protected] > > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > > > > > Matt > > The formulae given in Johnson and Graham's "High speed Digital Design" > are reliable. > > However there's no substitute for measurement to check your calculations, > > Bruce > > _______________________________________________ > time-nuts mailing list > [email protected] > https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > _______________________________________________ time-nuts mailing list [email protected] https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
