A flexible miniaturized square-ring UHF RFID tag antenna with circular polarization

Abstract

The conventional UHF RFID tag antennas are usually without good circular polarization characteristics on the flexible surface under the condition of miniaturization. In this paper, a novel flexible miniaturized square-ring UHF RFID tag antenna with circular polarization operating at 912MHz-934MHz is proposed. This tag antenna consists of a chip, a double feed line, a meander line, and an inductive matching loading structure. The simulated results indicate the proposed antenna is more suitable for working on flexible surfaces than the compared tag antenna. The measured result shows the reflection coefficient of RFID antenna within 840MHz∼960MHz meet the target requirements.