一种带宽展宽的等离子体超材料吸波体的设计

Design of a band enhanced absorber based on plasma metamaterial

为了在TE波下获得带宽可展宽(11GHz～14GHz频带内)且可调谐的吸收曲线,提出了一种新型超材料吸波体,其周期性结构单元采用蜂窝状特有的六边形结构。对该吸波体的参量分析图进行了计算,研究了变量g和d的数值不同时,对吸波体吸收频带及吸收带宽的影响,并解释了蚀刻"十"字形结构吸波体带宽展宽的成因。结果表明,该吸波体在9.17GHz～9.5GHz低频频域的吸收率达到90%以上,当不同的等离子体谐振区域被激励时,可以实现吸波体的分时分频域吸收以及改善吸波体的吸收性能,改变变量g和d可以实现对吸收频带的动态调控;可以通过在方形结构中蚀刻"十"字形结构的方式拓宽高频频域的吸收带宽,其在12.08GHz～13.91GHz频域的吸收率高于90%,改变变量s可以明显展宽吸收频带,且该吸波体对入射电磁波的角度不敏感。该吸波体的设计思路为拓宽吸波体的吸收带宽提供了一种有效的方法。

In order to achieve the absorption curve with broadening(within 11GHz^14GHz band)and tunable bandwidth under TE wave,a new metamaterial absorber was proposed whose periodic structural unit adopted honeycomb-shaped hexagonal structure.The parametric analysis chart of the absorber was calculated.The effects of variables g and d on absorbing band and absorbing bandwidth were studied.The cause of bandwidth broadening of the etched cross-shaped absorber was also explained.The results show that,absorption rate of the absorber in the low frequency domain at 9.17GHz^9.5GHz is over 90%.When different plasma resonance regions are excited,the time-frequency domain absorption of the absorber can be realized.And the absorptive capacity of the absorber can be improved.By changing the variables g and d,the dynamic control of the absorption band can be realized.The absorption bandwidth in the high frequency domain can be widened by etching cross-shaped structure in a square structure.Its absorption rate in the frequency domain of 12.08GHz^13.91GHz is higher than 90%.By changing the variable s,the absorption band can be obviously widened.The absorber is insensitive to the angle of incident electromagnetic wave.The design idea provides an effective way to broaden the absorption bandwidth of absorbers.