UHF-RFID SAR robotic inventory and localization: handling systems vs. multi-antenna solutions

UHF-RFID Synthetic Aperture Radar (SAR) Robotic-based localization and inventory systems are now widespread in literature. As known from the SAR theory, the tag localization accuracy along a given spatial direction depends on the antenna motion along the same direction. Indeed, the overall accuracy of the system depends on its capability to also determine the height from the floor of the RFID tag. This paper proposes a comparison between exploiting two antennas at different fixed heights or a single moving antenna hooked to a handling system that describes a vertical motion to localize the tag in the 3D space. The accuracy of the system is investigated with respect to the Signal-to-Noise-Ratio and a discussion on design criteria for the best system is given.