Development of Chipless RFID Sensors for agriculture applications

Abstract

Radio frequency identification (RFID) is growing rapidly and is being used in different fields for identification of objects. Radio Frequency Identification (RFID) refers to a wireless system comprised of two components: tags and readers. The reader is a device that has one or more antennas that emit radio waves and receive signals back from the RFID tag. RFID system is further divided into three types: Chip based RFID, Chipless RFID and hybrid RFID. Chip based RFID has silicon IC for storage of data which makes it expensive and it also requires power source. In contrast, chipless RFID has no silicon IC which makes it completely passive design requiring no external battery source and is also cost effective. This thesis presents a chipless RFID tag design that incorporates moisture level sensing. The tag is based on hexagonal resonators fabricated on Rogers 4350B substrate with dielectric 3.66 and loss tangent 0.0037. The tag is suitable for precision agriculture application where efficient resource management is required.