Polarization

I am trying to do a circular polarization with a PIFA, by simulating under HFSS.
But I tried different designs but none of them satisfy this constraint.
If you have any ideas please answer me.

Thanks a lot
Ludovic

Does it have to PIFA ?

What do you mean by your question ?

By definition PIFA has linear polarization (PIFA is degenerating from Inverted L, which is a bended monopole).
To get circular polarization using PIFA you have to use an antenna array of at least 4 antennas.
There are other ways to get circular polarization (making slots in antenna) but I think the efficiency is getting worst.
http://www.ansoft.com/news/articles/wlan.pdf

Hi Vfone, but my antenna should be integrated in a mobile phone, so it should be very small

So, use the second option that I specified.

But have you got any ideas of a design ?