This paper presents a method to increase the detection range for RFID readers in the UHF radio band. The design is following especially the ISO 18000-6C standardization demands for the UHF band, operating from 865 to 868 MHz in Europe and from 902 to 928 MHz in North America. These regulations are allowing the RFID tags to operate near the metallic surfaces and in a wider range than its counterparts at lower frequencies. The paper highlights the advantages offered by the array antenna, especially by the beamforming to increase the reader surveillance zone. The paper describes some additional techniques that are allowing the usage of the circular polarization to increase the reader sensing range and to improuve detection. The design starts with simulation and optimization using HFSS and ends with the measurements that validate the simulation results.
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