What is the trace width of IFA?

Hi friends,
I want to design an IFA in FR4,i design the dimension ,but i do not know how to select the trace width,and what will happen about the trace width difference.Anyone can tell me?
Thanks,

There is no special formula for trace thickness of IFA, but have to know that IFA frequency bandwidth increases with its thickness.

Thanks,vfone.I mean if i design integrated IFA in FR4 ,whether trace width effect the resonate frequency?for some documents introduce only the length,not refer to the width.which antenna parameters the width will effect ?

Only the bandwidth will be affected.

Thanks.