any one can help with design of a microstrip reflectarray in HFSS

Hi,

I am trying to design a microstrip reflectarray fed with a offset horn antenna. And I have some questions.

1) Unit cell and phase curve
How can I model a unit cell in HFSS such that all the information can be included? For example, the incident wave is close to but not exactly a plane wave and thus the incident wave angle for each array element is different. To achieve different phase delay, an array element is different from the surrounding elements. Then how should the boundary condition be set up for the unit cell simulation?

2) Array simulation
Do I actually have to simulate the whole array in HFSS? I am asking this because my computer memory is 16G. In order to achieve the accurate result, I should use the field from the horn antenna to excite the reflectarray. In that case, do I have to design a horn antenna in a separate HFSS project and then link its result to the reflectarray one? But, is there a simpler way to design the illuminating wave so that I can work only in the reflectarray project without losing too much of accuracy?

Thanks a lot.

Hi
for calculating the reflection phase of the radiation element, you must simulate the element with the floquet port and consider plane wave with different incident angle at hfss software.