Long range metal mountable tag antenna for passive UHF RFID systems

Development of a long range platform tolerant metal mountable patch-type tag antenna for passive ultra high frequency (UHF) radio frequency identification (RFID) systems is discussed. Results from full-wave electromagnetic simulations are presented to explain the design procedure and to evaluate the performance of the prototype tag antenna. The design uncertainty is quantified based on the expected maximum variations in the tag antenna and tag chip impedance. Wireless RFID measurements based on the EPC Generation 2 protocol are used in experimental tag design verification. The prototype tag achieves 25-meter maximum theoretical line of sight read range on metallic objects at 915 MHz.