基于石墨烯的多功能超表面设计

A graphene-based multi-function metasurface

摘要:

为实现机载天线罩吸波/透射波/反射波功能一体化，设计了一种基于石墨烯和光电二极管(PIN)的宽带吸波/反射波/透射波多功能超表面。当PIN正向导通时，超表面对入射电磁波的透过率接近于0，反射率可以通过改变石墨烯的费米能级进行调节；当石墨烯的费米能级为0.3 eV时，超表面在1.55~5.51 GHz范围内的吸收率超过了90%；当石墨烯能级为0 eV时，超表面在1.55~5.51 GHz范围内的反射系数高达45%。当PIN反向截止时，超表面在4.76 GHz处出现了一个透射峰，石墨烯费米能级为0.3 eV和0 eV时的透射系数分别为61%和71%。设计的超表面具有结构简单、宽带吸波/反射波/透射波多功能等优点，在通信和雷达等领域具有广泛的应用前景。

Abstract:

In order to achieve the integrated function of absorption/transmission/reflection of airborne antenna covers, a multifunctional metasurface based on graphene and Positive Intrinsic-Negative(PIN) diode is presented, which bears the function of wideband absorption/refection/transmission. When the PIN diode operates in forward biased condition, the transmittance of the metasurface is close to 0, and the reflection can be adjusted by changing the Fermi energy of graphene. When the Fermi level of graphene is 0.3 eV, the absorption of the metasurface is more than 90% from 1.55 GHz to 5.51 GHz, and the reflection coefficient is 45% at this band with the graphene energy level of 0eV. On the contrary, with the PIN diode acting in reverse biased condition, a transmission peak appears at 4.76 GHz with the transmission coefficients of 61% and 71% respectively when the Fermi level of graphene is 0.3 eV and 0 eV. Due to its advantages of having a simple structure, wideband absorption, and switchable refection/transmission, the proposed metasurface shows the potential in the fields of stealth of communication equipment and radar.