Design and Characterization of a Compact Single Layer Modified S-Shaped Tag Antenna for UHF-RFID Applications

摘要

In this paper, we report the design of a new compact single layer modified S-shaped tag antenna for UHF-RFID applications. To achieve a compact size of 51×34 mm2 for this tag antenna, the technique of using S shaped strip is applied, and by further adding a pair of equilateral triangular stubs into this structure, good impedance matching can be obtained at 915 MHz, which is the center frequency of the North-American UHF-RFID band (902 to 928 MHz). Besides exhibiting acceptable 5m read range in free space at 915 MHz, the proposed design shows a read range of about 4.5 when mounted on a metallic object (200 ×30 cm2) separated by spacer foam of thickness 1 cm. Furthermore, the proposed design shows a reasonable read ranges when it is mounted on different dielectrics with low permittivity. The proposed design has a simple configuration, low cost, acceptable read range, and can work on various background materials.