Reflectarray pattern optimization/phase-only synthesis to decrease the side lobe

Hello all,

Anyone has experiences on this topic: reflectarray pattern optimization or phase-only synthesis? It is aim to decrease the SLL. I checked some papers, and some people are using Intersection approach, or GA algorithm.

I am wondering what's the procedure to do phase-only synthesis on reflectarray? I think I have to write own code to calculate the pattern of reflectarray first. Then what should I do?

Thanks.
Panou