基于方形单开口环超材料的有源频率选择表面设计

Design of Active Frequency Selective Surface based on Square Single Opening Ring Metamaterials

设计了一种基于方形单开口环超材料的有源频率选择表面,由尺寸为7 mm×7 mm×0.25 mm的方形单开口环超材料单元体按10×10的周期排列构成,超材料单元体的介质基板采用FR4材料,在表面敷上方形单开口环铜片,能够在1~10 GHz(L、S、C、X频段)内保持介电常数、磁导率和折射率同时为负数。阐述了S参数反演法的推导过程,同时通过S参数反演法,证明该结构体是符合超材料性能的。在单元结构体之间加载可变贴片电容,通过改变加载在有源器件两端的电压大小,实现有源频率选择表面的谐振频率可调性。

An active frequency selective surface based on square single-opening ring metamaterials is designed which consists of 10×10 square ring metamaterial elements.Each element size is 7 mm×7 mm ×0.25 mm which is fabricated on FR4 substrate,and the single-ring square copper plate is mounted on the surface of the substrate. The element can maintain the dielectric constant and the permeability as well as the refractive index simultaneously negative at the range from1 GHz to 10 GHz（ L,S,C,X band）. The derivation process of S parameter inversion method is reviewed. At the same time,the S parameter inversion method is employed to prove that the element is consistent with the properties of metamaterials. A variable chip capacitor is loaded between the metamaterial elements,and the resonant frequency adjustability of the active frequency selective surface is achieved by changing the magnitude of the voltage at the two ends of the capacitor.