Passive ultra high frequency radio frequency identification systems for single-item identification in food supply chains

In the food industry, composition, size, and shape of items are much less regular than in other commodities sectors. In addition, a wide variety of packaging, composed by different materials, is employed. As material, size and shape of items to which the tag should be attached strongly influence the minimum power requested for tag functioning, performance improvements can be achieved only selecting suitable radio frequency (RF) identifiers for the specific combination of food product and packaging. When dealing with logistics units, the dynamic reading of a vast number of tags could originate simultaneous broadcasting of signals (tag-to-tag collisions) that could affect reading rates and the overall reliability of the identification procedure. This paper reports the results of an analysis of the reading performance of ultra high frequency radio frequency identification systems for multiple static and dynamic electronic identification of food packed products in controlled conditions. Products were considered when arranged on a logistics pallet. The effects on reading rate of different factors, among which the product type, the gate configuration, the field polarisation, the power output of the RF reader, the interrogation protocol configuration as well as the transit speed, the number of tags and their interactions were statistically analysed and compared.