Title :
An UHF reader antenna design for near-field RFID Applications
Author :
Liu, Hsien-Wen ; Yang, Chang-Fa ; Weng, Chung-Hsun ; Kuo, Huang-Lin ; Wu, Kuo-Hsien ; Lin, Yu-Shu
Author_Institution :
Dept. of Electr. Eng., Nat. Taiwan Univ. of Sci. & Technol., Taipei, Taiwan
Abstract :
In this paper, two UHF reader antennas based respectively on inductive and capacitive couplings for near-field RFID applications are presented. To identify item-level tags with inductive coupling, a loop-type antenna is developed to have strong magnetic fields in near zone. As for the capacitive coupling, a near-field focusing circular patch array fed by a network with various input phases for radiation elements is proposed to enhance the electric field in near zone. Thus, dipole-like tags can be recognized with the capacitive coupling. Measurements show that those antennas operating with commercial readers provide good performance of tag identifications for near-field RFID applications with inductive and capacitive couplings, respectively.
Keywords :
UHF antennas; antenna radiation patterns; loop antennas; microstrip antennas; radiofrequency identification; UHF reader antenna design; capacitive couplings; circular patch array; inductive couplings; loop-type antenna; near-field RFID applications; radiation elements; Couplings; Current distribution; Dipole antennas; Magnetic field measurement; Magnetic fields; Microstrip antenna arrays; Near-field radiation pattern; Phased arrays; Radiofrequency identification; UHF antennas; RFID; UHF reader antenna; capacitive coupling; inductive coupling; near-field;
Conference_Titel :
Microwave Conference, 2009. APMC 2009. Asia Pacific
Conference_Location :
Singapore
Print_ISBN :
978-1-4244-2801-4
Electronic_ISBN :
978-1-4244-2802-1
DOI :
10.1109/APMC.2009.5385466
