momentum ads tutorial

http://edocs.soco.agilent.com/displa...icrostrip+Line

Hi all, I only found the link above for ADS momentum optimizer tutorial but I don't quite understand how L is setup in finding the right microstrip line length such that the phase difference is 120deg.

Could anyone please post a more informative tutorial on using the ADS optimizer in momentum as I only currently only know how to do it in schematic and not momentum.

Thanks in advance.