"A new identification technology" RFID-radar represents a major technical development in the technology of Radio Frequency Identification (RFID). Before the arrival of RFID-radar, readers have been able to read the identity of multiple transponders in a zone at one time, but they have not been able to locate where in the zone the transponders actually are physically.

As the performance of readers and transponders improve, operating ranges increase giving one reader the ability to monitor larger areas meaning location information in addition to the identity information becomes very important. RFID-radar works with very low cost transponders and relatively cheap reader systems.
http://www.rfid-radar.comhttp://www.rfid-radar.com/brochure.pdf

Selling price of the Prototype RFID-radar is < EURO 2560 plus freight