Passive Enhancement of Read Range of Miniaturized UHF RFID Tags

This paper presents a passive structure to improve the read range of miniaturized UHF RFID tags attached to small metallic objects. The improvement is realized by coupling the tag antenna to two auxiliary radiating structures (ARS) deported from the tagged metallic object (TMO). Low cost proof-of-concept prototypes were realized on a FR4 substrate. Measurement are in good agreement with simulations. Read range was increased by a factor of 7 in the worst cases and 25 in the best case, from 20 cm without the ARS up to 1.44 m and 5 m respectively with the ARS.