Microstrip patch antenna array for coverage and range extension of RFID applications

Official URL: http://192.168.1.20/record=b1228182 (Table of Contents)

Passive UHF RFID systems have various advantages over other RF based identification systems despite the lack of operation range and coverage as other passive systems, which is one of the main obstacles of this promising technology. To increase the operation range and the coverage, in this thesis, phased antenna array for passive UHF RFID applications designed, implemented and measured. As a part of the phased antenna array design, a feed network, which will sustain the necessary amplitude to each radiating element and phase difference between them, is designed. This feed network design is composed of the separately design of phase shifter and power divider. Also as the radiating element, a microstrip patch antenna element is designed and implemented. After calculating the response final array structure with use of a phase shifter, power divider and microstrip patch antenna, to obtain beam steering between ±30 degrees, the antenna array is implemented on PTFE woven-glass ceramic composite substrate with a dielectric constant of 4.5. From the radiation pattern measurements in the compact test range and experimental test results obtained in actual RFID system, it is observed that the operation range and coverage are increased. Also, it is acknowledged that compact test range and field tests of antenna array are consistent with each other. As a final remark, due to time averaging while steering between the main beams, without causing any issue with the ETSI regulation limits on ERP (effective radiated power), operation range and coverage can be expanded.