Robust UHF RFID antennas in complex environments

This paper discusses the main issue of commercial RFID tags, which is the reduced range of the RFID tags when placed in the proximity of complex environments (e.g. food or human bodies). A short overview of the design aspects of UHF RFID antennas in complex environments is presented. Water, blood, heart and muscle tissue are used as environments. An antenna with a protecting ground plane that reduces environmental influence is presented. Several system-level measurements were done in order to compare the prototype (including and embedded IC) with commercially available RFID tags. In addition, a robust antenna with a reduced size (factor of 5) is presented with an efficiency of 84% at 868 MHz when placed on a water tank.