trying to make horn antenna

Can anybody help with making a horn antenna? I'm just starting and am trying to build one for the upcoming science fair. I want to be in the 2.4 GHz range. Any help will be much appreciated.

Try here
http://www.qsl.net/n1bwt/contents.htm

try with SuperNEc software http://www.supernec.com/downloads.htm

there is a predefine horn antenna simulation

:D

Or you could just use a baked bean can....... No its not a joke.............