Low Cost Passive UHF RFID Packaging with Electromagnetic Band Gap (EBG) Substrate for Metal Objects

Passive UHF (Ultra High Frequency) RFID (Radio Frequency Identification) is a promising technology for products tracking in logistics or routing packages in supply chain. However, the RFID tag is significantly affected by objects surround it especially metallic objects. In this paper, we disclosed a new method using electromagnetic band gap (EBG) material to insulate the UHF RFID tag from backside objects, so that the tag could work on water surface and even metal. The design of EBG material for UHF RFID which operates at 915 MHz was discussed in this paper. An ultrathin (<1.5 mm) tag on metal with a gain of 4 dBi was achieved in simulation and a prototype of 2.93 mm thick RFID on metal tag was measured in experiment. The simulation results showed that the RFID tag still could be read on EBG substrate with a good gain (~4 dBi). The measurement results indicated that the read rang of RFID tag with EBG substrate could reach up to 4 meters on metal template.