Need Help! EBG in IE3D

Hi, all
Currently i face a problem on how to simulate EBG patch antenna, i dont know wheter i draw correct or not. I still a new guy in IE3D. Hope some1 can help me. Coz when i compare the return loss graph between patch antenna with and without EBG, the result almost same, and bandwidth didnt increase. I try trouble shoot it, by increase height EBG, via or without via, shape (circular, mushroom square, or fractal EBG) also not different. I feel so down, really hope some1 can help me. Thanks a lot

HI, lohwenkit:

They look good. However, for the 3rd one, it looks like the xy size of the EBG is small compared to the patch. EBG may allow you to reduce the height of the patch to the EBG gnd while you can enhance the bandwidth. This is due to the fact that it tries to confine the resonant energy in the structure in the EBG area. The energy will spread to more space in the XY locations instead of being confined below the patch in a typical patch antenna. You do need the EBG size to be significantly larger than the patch in order to get the benefits of EBG. Regards.

Hi Jian
Can you help me -step by step- to design an easy ebg with IE3d?

thanks