摘要
针对兼具通带内非对称传输与通带外强反射抑制功能的微波复合材料设计问题,提出了一种基于手性超表面和电路模拟有耗层的级联设计。借助缝隙耦合的双层金属栅结构,手性超表面在透波通带内呈现出与来波方向相关的非对称极化扭转特性。同时,通过在集总电阻加载的双方环导电条带中引入LC谐振器,获得具备频率及极化选择透波特性的电路模拟有耗层。进一步,利用手性超表面在非对称透波通带外的强反射特征,由手性超表面和电路模拟有耗层的级联形成吸透复合结构。对来自于+z方向的法向入射波,所设计的复合结构可在7.17 GHz附近实现非对称因子为86.2%、插入损耗为0.65 dB的透波通带;而在非对称透波通带以外的低频端和高频端,复合结构可分别在134.2%与127.4%的相对带宽内对x极化与y极化来波实现不低于10 dB的有效吸收。由此,在宽频吸波带中引入了一个非对称透波窗口,有益于潜在应用平台的低散射特性。
In order to achieve the microwave composite material with both in-band asymmetric transmission and out-of-band reflection suppression,a cascade design based on a chiral metasurface and a circuit analog lossy layer was proposed.With the slot-coupled bi-layered metallic gratings,the chiral metasurface exhibits the asymmetric polarization conversion,which depends on the direction of the incoming wave,in its passband.Meanwhile,a frequency-and polarization-selective circuit analog lossy layer was obtained by introducing LC resonators into the double-square-loop conducting strips loaded with lumped resistors.Furthermore,by utilizing the out-of-band strong reflection of the chiral metasurface,the composite rasorber structure was formed through cascading the chiral metasurface and the lossy layer.For the normal incidence originating from+z direction,the designed composite rasorber structure yielded a passband with an asymmetric factor of 86.2%and an insertion loss of 0.65 dB around 7.17 GHz.Within the lower and upper bands beside that passband,the composite rasorber structure achieved the effective absorption of at least 10 dB within the fractional bandwidth of 134.2%and 127.4%for x-and y-polarized incidence,respectively.As a result,an asymmetric transmission window can be designed within a wide absorption band,which is beneficial for the low scattering performance of the potential application platforms.
作者
张润午
尚玉平
廖成
ZHANG Runwu;SHANG Yuping;LIAO Cheng(Institute of Electromagnetic Field and Microwave Technology,School of Physical Science and Technology,Southwest Jiaotong University,Chengdu 610031,China)
出处
《电子元件与材料》
CAS
北大核心
2023年第8期988-995,1002,共9页
Electronic Components And Materials
基金
国家自然科学基金(61601379,61771407)。
关键词
吸透结构
手性超表面
雷达波吸收材料
非对称传输
rasorber
chiral metasurface
radar absorbing material
asymmetric transmission
