ring-shaped patch antenna

I am designing a ring-shaped patch antenna. I am using MGRID as the layout editor. How can i optimize the inner and outer radii of the ring?

You can do it. However, it can be tedious. You create a ring patch with 16 segments. Each segment is 22.5 degrees. You will have vertices at phi = 0, 22.5, 45, ... 157.5 degrees. What you can do is to define the vertices at phi = 0 for the 1st variable. Then, you select the ones at 22.5 degrees and OPTIM->ADD SELECTED .. You define its Tuning Angle = 22.5 and Tuning Rate = 1. Do it for all the vertices at all the angles one by one. You are able to define the radius as a variable. Do it for both inner and out radii. It is tedious. However, if you want to use IE3DLIBRARY for it. It is very simple.