基于电阻膜的宽频带超材料吸波体的设计

Design of a wide-band metamaterial absorber based on resistance films

基于电阻膜设计了一种宽频带、极化不敏感和宽入射角的超材料吸波体.该吸波体的结构单元由六边形环状电阻膜结构、介质基板和金属背板组成.仿真得到的反射率和吸收率表明,该吸波体在7.0—27.5GHz之间对入射电磁波具有宽频带的强吸收,证实了电路谐振相对于电磁谐振易于实现宽带吸波.仿真得到的不同极化角和不同入射角下超材料吸波体的吸收率表明,该吸波体具有极化不敏感和宽入射角特性.仿真得到的基板和电阻膜对超材料吸波体吸收率的影响表明,电阻膜结构和金属背板之间形成的电容以及电阻膜结构的电阻都存在一个最佳值,此时电路谐振最强、吸收带宽最大.

A wide-band,polarization-insensitive and wide-angle metamaterial absorber is presented,which is based on resistance films.A unit cell of the absorber consists of a hexagonal resistance film,a substrate and a metal backboard.Simulated reflectances and absorbances indicate that this absorber has a wide-band strong absorption for the incedent wave from 7.0 GHz to 27.5 GHz,indicating that electrocircuit resonances are more suited to realize a wide-band strong absorption than electromagnetic resonances.Simulated absorbances under different polarization angles and different incident angles show that this absorber is polarization-insensitive and angle-wide.Simulated influence of substrate and resistance film on the absorbance of the absorber indicates that there exist optimal values for the capacitance between the resistance film and the metal backboard and for the resistance of the resistance film,where electrocircuit resonances are strongest and the absorption band is widest.