Locating RFID Tags by Rotation

Locating objects labeled with RFID tags is an important issue which should be addressed in many applications, such as warehouse management, goods management in supermarket and finding of lost objects. Some existing works use large numbers of reference tags which involve lots of manpower to deploy them. Others achieve high accuracy, but rely on sophisticated equipments which are hardly available in large scale to the industry. This work exploits the radiation pattern of existing directional panel antenna which is steerable and derives angle-of-arrival(AoA) information from the energy reflected by the target tag when the antenna is rotating. We use Commercial Off-The-Shelf (COTS) equipments and get median position accuracy of 29cm in our preliminary experiment.