LF-RFID spiral loop antenna for conveyor belt applications

This paper presents the spiral loop antenna for low frequency radio frequency identification (LF-RFID) in conveyor belt applications. The structure of spiral loop antenna can provide the magnetic field distribution of each principal component (Hx-, Hy- and Hz-component) to enhance the communication distance in all principal directions. The overall size of antenna is 55 cm × 60 cm. The antenna was fabricated with 24 AWG copper wire and fed by BNC-connector. The numerical electromagnetics code (NEC) is employed to analyze the magnetic field distribution and communication performance in each principal component. The antenna prototype was fabricated to confirm the communication performance between reader and tag. From the measured results, the spiral loop antenna has the percentage of surface equal to 76.34%, 98.96% and 67.56% in x-, y-, and z-directions, respectively. For the measured results with the conveyor belt applications, it is found that the percentage of surface is 42.50% in x-direction, 100% in y-direction, and 95% in z-direction, respectively.