dual pifa antenna for wlan 2.4ghz/5.5ghz

i am designing dual band pifa for wlan 2.4 and 5.5 ghz by using cst suite 2011, so please if there is any one who knows where i can find tutorials of cst to design this type, it will be a lot for me.

and also designing pifa, do i need to use substrate such as fr4 or just air and i want to use the material for copper,bu dont have any idea about the thickness of the copper.so if you have any idea about this design please help

thank you