Performance Improvement of Meandered Line RFID Reader Antennas for UHF Near Field Applications

This research looks into and analyzes in detail the design of a meandered line RFID reader antenna, which is mainly meant for near-field applications. The Ultra-High frequency (UHF) band, which spans from 840 MHz to 960 MHz, is where the antenna operates. The scope of the study involves the comparative study of design variations of the RFID reader antenna, which involves the insertion and deletion of the U-shaped section within the meandered line antenna design and the E-shaped middle section within the meandered line antenna design. The following design variations demonstrate an improvement in the overall gain and polarization pattern of the antenna. In addition to this, the antenna designs depict a lower far-field gain that prevents the incorrect reading of designated targets outside the near-field region. Circular polarization is observed when the U-shaped section is incorporated within the antenna design, which exhibited a return loss of [S11] = -13.25 dB, near-field antenna gain of - 4.73 dBi, and an operating frequency of 878.8 MHz, which covers the UHF RFID range. The proposed antennas are designed and simulated using Computer Simulation Technology (CST) Microwave Studio software.