超材料吸波体的高灵敏度微波传感器

A High-Sensitivity Microwave Sensor Based on Metamaterial Absorbers

超材料吸波体具有超薄和强谐振等特点,可用于高灵敏度传感。设计了微波段可用于检测介质折射率的超材料吸波体传感器,通过仿真设计和参数优化,得到了工作频段内单频点谐振、高吸收的吸波结构,分析了其吸波机理。吸波体表面加盖不同折射率的介质板,会导致谐振吸收频点发生不同幅度的频移,经分析,当介质板厚度大于2mm时,谐振吸收频点偏移仅与待测板折射率有关。通过对仿真数据进行拟合,得到了谐振频率与折射率之间的线性函数关系并分析了传感器的性能,最后实验验证了二者的函数关系。设计的超材料吸波体传感器灵敏度达到了1 592MHz/RIU,FoM值达到7.026 9/RIU。

The meta-material absorbers have characteristics of low profile and strong resonance,and can apply to high-sensitivity sensing.This paper designs a microwave metamaterial absorber sensor with the aim of detecting the refractive index of dielectric plates.Through the simulation design and the optimization,the paper obtains a high-absorption absorber structure and analyzes the absorption performance and mechanism.The refractive index and thickness of the dielectric plate may result in the resonant frequency and absorption amplitude of the absorber.When thickness is larger than 2mm,the resonant frequency is subject to approximate influence from the refractive index,and the influence of thickness is negligible.Through simulation and parameter fitting,linear function between the resonant frequency and refractive index is obtained.The major advantages of the metamaterial absorber sensor are high in sensitivity,high in FoM value and good in linearity.The frequency sensitivity and FoM value achieve 1 592 MHz/RIU and 7.026 9/RIU,respectively.The absorber sensor also has potential application values in thickness and incident angle sensing.