Far field radiation pattern-HFSS

Hi all,

hope anyone could help me with this. I'm confused.
when simulated a microstrip antenna(from a paper) the return loss was as expected but the radiation pattern is NOT.
could the return loss be right and the radiation pattern wrong? it is the same antenna and return loss tells it's radiating well.

Any ideas for improving the far field radiation pattern?
Any explanations?

thanks in advance.

Can you post an image of both the antenna and the rad. pattern and tell us why it is wrong? Are you simulating over infinite ground and or infinite dielectric layers?