基于2.5维小型化设计的UHF频段高性能超材料吸波体

High-Performance Metamaterial Microwave Absorber Based on 2.5-D Miniaturization Design in UHF Band

提出一种基于2.5维小型化设计的高性能超材料吸波体,其吸波频带覆盖全球范围内超高频射频识别(Ultrahigh-frequency radio frequeny identification,UHF-RFID)系统工作频段。该吸波体结构借助多个金属化过孔增加回路电长度进行小型化并拓展吸波带宽,通过单独调节上下表面衰减电阻阻值缩小此过程中介质板厚度带来的极化差异。单元尺寸被缩小至13.6 mm×13.6 mm,约为中心频率波长的1/60。仿真和实验结果表明,该2.5维小型化高性能超材料吸波体在840~960 MHz的频带范围内平均吸收率超过99%,相比已公开文献,95%吸波带宽提高45%以上,可用于改善受限空间中RFID系统的可靠性。

A high-performance metamaterial absorber based on 2.5-D miniaturization design is proposed in this paper,whose absorbing band covers the UHF radio frequency identification(RFID)operation band worldwide.The absorber uses metallized vias to increase electrical length and expand absorption bandwidth.Polarization difference caused by the thickness of the dielectric in this process can be reduced by adjusting resistance of the upper or lower layer separately.Size of the unit cell is miniaturized to 13.6 mm×13.6 mm,about 1/60λat the center frequency.Detailed simulation and experimental results show that the 2.5-D miniaturized high-performance metamaterial absorber has absorptivity of more than 99%among 840—960 MHz on average.Compared with the results in published literature,the 95%absorption bandwidth is increased more than 45%.Thus,the absorber can be used to improve the reliability of RFID systems in restricted spaces.