Effective dielectric constant

Hi, u guys know how to find effective dielectric constant with given of Impedance(Ohms)?
i know there is a table of Data From various Microstrip Lines in the feed Network.
U guys know where to find? pls help?

Are you looking to calculate the impedance given

?
Take a look at this document Advanced Circuit Materials
I am sure you can find a lot more documents on the web. Just try a google search.

Best regards,
v_c

Hay suyan,
try downloading "txline"
it's a small program that helps design transmission lines
you can than insert you parameters to get you answer.

Sag