Microstrip and CPW higher order modes

Hi all,
Can anyone give me a reference or a formula ( approximate is fine enough ) to calculate the frequency at which the first higher order mode ( non Quasi - TEM )starts propagating in a microstrip and/or a CPW ? Thanks a lot.

-svarun

Hi svarun

I think this might help you. It took me a while to scan in for you, so this is the reason for delay.

flyhigh