Planar RFID Tag Antenna Based on Combined Matching Techniques at 902 MHz

In this article, a planar UHF RFID tag antenna is presented which is designed by amalgamation of three impedance matching approaches: Nested slot, T-match and Meandered Inductive Loop (MIL) network. The tag antenna has volume of $76 \mathrm{~mm} \times 30 \mathrm{~mm} \times 1.6 \mathrm{~mm}(0.228 \lambda \times 0.0902 \lambda \times 0.0048 \lambda)$. The planar structure of tendered antenna can reduce mass production cost of tags. Moreover, the slot based T-matching and MIL network rotation can be tuned in large scale for impedance matching. The presented tag antenna extends its read range upto 14.1m.