An inductively-feed loop tag antenna close to a human body for UHF RFID applications

This paper presents a UHF RFID loop tag antenna for on-body applications. The proposed one-wavelength loop fed by an inductively coupled loop is printed on a PVC card and put close to a human body. The proximity effect due to the human body is considered in the design stage. The human model is composed of a four-layer stratified elliptical cylinder. The designed tag was constructed and experiment was performed to measure reading ranges. The measured reading range achieves about 5 meters when the tag is pasted on the chest of a human body.