基于等效介质原理的宽角超材料吸波体设计  

Design of wide-angle metamaterial absorbers based on equivalent medium theory

作　　者：吴雨明 王任[1] 丁霄[1] 王秉中[1] Wu Yu-Ming;Wang Ren Ding;Xiao Wang;Bing-Zhong(Institute of Applied Physics,University of Electronic Science and Technology of China,Chengdu 611731,China)

机构地区：[1]电子科技大学,应用物理研究所,成都611731

出　　处：《物理学报》2020年第22期304-312,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61731005,61901086);博士后创新人才支持计划(批准号:BX20180057);中国博士后科学基金(批准号:2018M640907);中央高校基本科研业务费(批准号:ZYGX2019J101)资助的课题。

摘　　要：超材料吸波体的吸波性能会受到电磁波入射角度的影响,角度不敏感的吸波材料设计一直是吸波材料设计的难点之一.本文基于等效介质原理设计了一种宽入射角超材料吸波体.超材料吸波体单元由竖直放置在理想导体(PEC)上的双面开口谐振环组成,谐振环开口处加载集总电阻R和集总电容C,其中电阻R用于调控超材料的等效电磁参数,电容C用于调控超材料的谐振频率和实现单元小型化.当TE波(横电波,电场方向与入射面垂直的平面电磁波)照射时,电阻R=4000 W, C=1.5 pF,在1.59 GHz处,本文设计的宽角超材料吸波体实现了70°内90%以上的吸波率,当入射角度达到75°,也仍然有85%以上的吸波率,并且基于等效介质原理的理论分析结果和仿真结果及测量结果都基本符合;当TM波(横磁波,磁场方向与入射面垂直的平面电磁波)照射时,电阻R=1200 W, C=1.5 pF,此时需将超材料单元旋转90°,在1.59 GHz处,本文设计的宽角超材料吸波体实现了70°内90%以上的吸波率,当入射角度达到75°,也仍然有85%以上的吸波率.测试结果基本与仿真结果符合.此外,当电容C发生改变而其余参数不改变时,本文设计的超材料吸波体在新的谐振频率处仍然具有同样的宽角吸波性能,具有宽频带的工作特性.The performances of metamaterial absorbers can be affected by the incidence angle of electromagnetic wave.It is difficult to design the incidence angle-insensitive metamaterial absorbers.In this paper,we propose a metamaterial absorber with wide-angle incidence based on the equivalent medium theory.The absorber unit consists of a double-sided split resonant ring placed vertically on the ground.The resistors and capacitors are loaded at the opening of the resonant ring.The resistor is used to adjust the equivalent electromagnetic parameters of the metamaterial,and the capacitor is used to control the resonant frequency of the metamaterial and miniaturize the unit.When the transverse electric(TE)plane wave impinges on the surface of the absorber,R=4000 Ohm and C=1.5 pF,the proposed absorber can achieve an absorptivity greater than 90%at 1.59 GHz up to an incidence angle reaching 70°.Besides,the absorber can achieve an 85%absorptivity under an incidence angle of 75°.when the transverse magnetic(TM)plane wave impinges on the surface of the absorbers,R=1200 W and C=1.5 pF,the proposed absorber can achieve an absorptivity of greater than 90%at 1.59 GHz up to a 70°incidence angle.Besides,the absorber can also achieve an absorptivity of 85%up to 75°.The results show that the measurement results are basically consistent with the simulation results.In addition,when the capacitance is changed while the other parameters are fixed,the metamaterial absorber proposed in this paper still has the same wide-angle absorbing performance at the new resonant frequency.In other words,the proposed absorber has broadband operating characteristics.A frequency-tunable metamaterial absorber with wide-angle incidence can be designed based on the aforementioned results.The results in this paper provide a method of tuning capacitance.The opening is set at the other end of the split ring,and the same fixed-value resistor and variable capacitor are loaded on the left opening,and the corresponding DC bias feeder is designed.One end of the DC

关 键 词：等效介质原理 宽入射角 超材料吸波体 

分 类 号：TB34[一般工业技术—材料科学与工程]