In this work, a compact, long read range, and an efficient spiral loop structure coupled tag antenna is proposed for UHF-RFID applications. Meandered line element is inductively coupled to spiral loop for matching its input impedance to Higgs-4 chip. Equivalent circuit of antenna is extracted to analyze its working mechanism in the operating band. Experimental characterization validates the performance of proposed tag antenna in free space and on cardboard sheet in terms of read range, tag sensitivity, and differential radar cross section with an EIRP of 3.28 W. The measured radiation pattern of the tag is found to be omnidirectional in H plane and figure of eight in E plane. The tag's read range is measured on objects like fiber, wood, plastic, and glass in outdoor scenario to study its environment tolerance. The tag antenna has volumetric size of 1736 mm 3 and read range of 13.6 m in US RFID band. K E Y W O R D S inductive loop feed, radar cross section (ΔRCS), read range, tag sensitivity, UHF (ultrahigh frequency) radio frequency identification (RFID) tag antenna
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.