Kind of reminds me of the old Channel Master 4251's (now discontinued) although the 4251 was a full circle design, not partial, and was about 7' across. http://www.rocketroberts.com/cm4251/cm4251.htm
Looks identical to the antennas used by one of the wireless Internet providers here a while ago.. They're now zip tying a rectangular plastic enclosed radiator to a recycled DN 18 inch dish on new installs.