无源超高频抗金属标签天线设计方法综述

射频识别（RFID）技术的不断发展,对标签天线提出了更高的要求。普通标签天线直接应用于金属表面时,由于受到金属边界的影响,其性能会出现一定程度的下降。详细介绍了4种无源超高频抗金属标签天线的设计方法,包括调整天线与金属面的间距、采用吸波材料、引入高阻抗表面基板、采用平面倒F天线（PIFA）或微带天线结构,并分析了每种方法的优缺点及其对标签天线的阻抗匹配、带宽、尺寸、识别距离以及成本等方面的影响。微带贴片天线不仅具有低剖面、高方向性等优点,而且含有金属接地板,常用作抗金属标签天线的设计原型。在抗金属标签天线的设计与实际应用中,研究者可针对具体要求灵活运用这些设计方法。

Overview of design methods for passive UHF anti-metal tag antennas

With the development of radio frequency identification(RFID)technology,tag antennas are required to possess higher performance. However,when a common tag antenna is directly placed on a metal surface,its performance degrades a lot due to the metallic boundary. For passive ultra-high frequency(UHF)anti-metal tag antennas,this paper introduces four design methods including adjusting the distance between antenna and metal surface,using absorbing material,introducing a substrate of high-impedance surface,and utilizing planar inverted-F antenna(PIFA)or microstrip antenna,and discusses each method''s properties and influences on impedance matching,bandwidth,size,recognition distance and cost etc. Microstrip antenna has not only low profile and high directivity,but also a metallic ground floor,so it is usually used as the prototype of anti-metal tag antennas. According to specific requirements,these methods can flexibly be applied to actual anti-metal tag antenna design.