This paper will address the theoretical and practical construction of a 2.4GHz horn antenna and methodology used in testing the antennas. The pyramidal horn antenna is part of the aperture antennas family that has a conical radiation pattern, linearly polarized and is ideal in high gain transmission and receiving, peer to peer communications, and as a dish feed.
http://www.engr.sjsu.edu/rkwok/projects/horn_B.PDF