Double-Layer Passive Tag Antenna for UHF RFID Applications

摘要

In this paper, a small tag antenna with double-layer substrate for UHF RFID application is presented. The proposed tag antenna comprises of a small loop that is a feeder part on upper layer and meandered dipole on the another layer of a paper substrate. Capacitive coupling and meander line techniques are working together to achieve small size. The overall size of proposed tag antenna is 30 x 26 x 0.35 mm^{3. In addition to a feature of small size, the proposed tag antenna can easily be re-designed in different operating frequency by modification only the feeder part. The input impedance can be matched well with the IC-chip impedance. It can be operated in the operating frequency range of UHF RFID (920-925 MHz in Thailand). The performance of the proposed tag antenna such as S-parameters, power reflection coefficient, radiation pattern, gain and read range are discussed in detail.}