dude, do your research on Google, and come up with something, tell us what you have tried before making us do the whole thing.
Its a very very interesting Q but google this and see what you came up with?
Like: FCC or FM regulations or FCC FM specifications
but the best was when I searched FCC (Federal Communication Commission). Actually you should know what FCC is. Look behind any digital device and you will find a logo F(c something. They are regulatory board for electronics and wireless. So here are some links:
How to light up and paint your antenna 
http://wireless.fcc.gov/antenna/inde...on_paint_light
Move down to antenna specs:
http://www.fcc.gov/mb/audio/includes/30-engrser.htm