基于集成平面阻抗匹配巴伦的新型UHF RFID近场天线

novel planar antenna with double-sided strip-line (D-S S-L) structure is developed in this paper for Ultra High-Frequency (UHF) Near-Field Radio Frequency Identification (RFID) applications. This antenna is composed of a microstrip feed network, an impedance transformer cell, a D-S S-L radiator and 8 resistors, which are fabricated on a single FR-4 substrate. Thus, it is very convenient to fix the antenna and the impedance-matching balun for its integrated structure. Meanwhile, the total fabrication difficulty is reduced and the production cost is decreased. The simulation and measurement results show that this antenna operates with symmetric magnetic field distribution in the near-field zone. And the gain is less than -3dB in the far-field zone. As a result, this antenna can effectively identify tags in the near-field zone but reduce the misreading in the far-field zone.