Passive UHF RFID printed monopole tag antenna for identification of metallic objects

A UHF printed meander monopole RFID tag antenna incorporating an artificial magnetic conductor (AMC) as the reflector is presented. The proposed antenna is designed to operate with a chip having an input impedance of 8.2-j61 Ω. For maximum power transfer between the chip and the antenna, T-Matching technique is implemented. The fabricated assembled tag is evaluated in both free-space and when attached to a metal plate. Measurements demonstrate achieving a maximum readable range of 10 m in free space and 8.3 m when the tag is placed on a metal sheet.