Influence of UHF Tags in the Different Material Surface to RFID System

RFID tags utilized on UHF band usually are passive tags, which could only work at high power density area, so analyzing distribution of radiation field and characteristics of transmission model is useful for designing a system when acquiring information. The identifying distance of UHF tags can reach 10 meters in the air environment, but the tags need to be affixed in the surface of different materials when it works, thus make identifying distance of RFID become shorter due to the effect to parameters such as dielectric constant, radiation efficiency, radiation impedance caused by the diversity of material properties. Based on application, the radiation field is analyzed by CST Microwave Studio when RFID tags are on the surface of different medium. Several material plates are applied with numerical simulation.