应用于金属环境的UHF RFID读写器天线设计

A Design of a UHF RFID Antenna for Metal Environment Applications

摘要: 为了满足集成、低剖面RFID手持读写器的需求，设计了一款小型超高频RFID读写器天线。该天线采用印制偶极子天线形式，体积为100 × 10 × 1 mm³，非常适合于手持式移动通信设备。本文的创新点是使用T型匹配电路用于读写器天线调节阻抗匹配，使其可以适应读写器内部金属环境的需求。测试结果显示，该天线在920~925 MHz频段匹配性能良好，驻波比小于1.2，同时峰值增益约为2 dBi。与相同应用环境的陶瓷介质微带天线相比，其具有读取距离远，低剖面，体积小、重量轻，成本低等优点。

Abstract: To meet the desire of integrated low-profile RFID handheld reader, a compact UHF reader antenna is proposed. This printed dipole, having a size of 100 × 10 × 1 mm³, is very suitable for handheld mobile communication devices. The proposed approach of T-match in this paper can adjust the input impedance of the antenna, and overcome the low impedance when the antenna is installed close to the metal components in the reader. According to the experiment, it shows that the im-proved antenna has an excellent impedance matching in the 920 - 925 MHz band and the SWR is less than 1.2, as the maximum gain is about 2 dBi. Compared with ceramic microstrip antennas for the same applications, this work has numerous advantages such as long reading range, low profile, integrability and low cost.