An Antenna System Design for UHF RFID Applications

Abstract

This paper presents an antenna system operating in the UHF band for RFID applications. The RFID module is deployed for LPG delivery and management and is incorporated as part of an embedded system. To reduce the space taken by the antenna, a folded meandered-patch monopole is adopted for the antenna of the handheld reader. On the tag side, in order to meet the low cost requirement, a printed dipole antenna is used with the passive tag. T-matching technique is employed to step up the input impedance so that the printed dipole antenna is conjugately matched with the RFID tag microchip manufactured by Texas Instrument (TI). The reader and tag antennas are designed and simulated using the HFSS software. Parameters including return loss, gain, and radar cross section of the antennas are evaluated. Then the simulated return loss of each antenna is compared with the measured result to verify the proposed design. In addition, radio link budgets that describe the backscatter power link of a passive RF tag are evaluated to estimate the read range of the RFID system.