s-params in spice - what's 3D

Hi,

I'm just reading an article that says you can include s-parameters in a
spice model by first converting them to y-parameters, & etc. So I want to
try this. But I don't understand his equations, so maybe I can get some
help.

To convert the parameters it says to do:

y11=3D((1-s11)*(1+s22) .......
y12=3D-2*s12 .....

and so on. So my question is what is "3D"?

I have searched for this but can't find any info, is this a key symbol or a
function or what?

TIA, jw


I know this is not a beginner question, but I don't have access to
sci.electronics so I posted here.

 

Hi,

Fill your boots -


http://www.rfcafe.com/references/electrical/s-h-y-z.htm


Cheers - Joe