左手材料全角度反射器的设计

Design of omnidirectional reflector composed of left-handed materials

利用传输矩阵理论,对左手材料(LHM)构成的一维光子晶体(PC)反射器的反射带特性进行了分析。研究结果表明,LHM反射器的全角度反射带(ODB)对入射角度是不敏感的,即具有全角度反射的功能。而右手材料(RHM)反射器的反射带对入射角度是非常敏感的,得到的是部分角度反射带。进一步分析发现,LHM PC反射带对周期数N不敏感,但会随着材料层厚度比k的增大,向高频方向移动,随晶格常数h的减小,向低频方向移动。在此基础上,提出了设计左手材料全角度反射器的方法,并得到了3.1~3.9GHz频段之间、反射率高达100%的全角度反射器。设计结果表明,本文思路可用于实现任意波段全角度反射器的设计。

Using the method of transfer matrix,the reflection band characteristi cs of one dimension （1D） photonic crystal （PC） structure composed of left-handed material s （LHMs） is analyzed.The simulation results show that the reflection band of the 1D PC structure with LHMs is not sensitive to the incident angle,and this kind of reflection band usually is called as “omnidirectional reflection band （ODB）”.However,the reflection ba nd of the PC crystal structure composed of the right-handed materials （RHMs） is very sensitive to inciden t angle,and we named this kind of reflection band as “partial angle reflection band”.Further study reve als that the omnidirectional reflection band of PC structure with LHMs is not sensitive to the change of period N.But as the thickness ratio k increasing,the position of the omnidirectional reflection band will move to the high frequency direction.Moreo ver,as the lattice constant h decreasing,the position of omnidirectional re flection band will move to the low frequency direction.Based on this,we design an omnidirectional reflector comp osed of LHMs.The reflector band is between 3.1GHz and 3.9GHz,and its reflectance is up to 100%.The design results can be used to design omnidirectional reflector with LHMs in arbitrary microwave band.