渐变折射率人工电磁介质设计与3D打印制造

Design and Fabrication of Gradient Index Artificial Electromagnetic Medium Based on 3D Printing

提出一种以物理性能驱动的人工电磁介质宏/微结构一体化设计与制造方法;以超材料尺度的光子晶体结构为研究对象,建立超材料单胞结构特征参数与等效介电常数及折射率之间的映射关系,实现渐变折射率人工电磁介质的可控设计;在理论计算的基础上,采用基于渐变折射率超材料结构设计了＂地毯式隐形罩＂、＂电磁黑洞＂等器件;以光固化3D打印技术为制造手段,光敏树脂为基体材料,实现具有复杂结构的三维电磁器件,并对其性能进行研究;结果表明,所设计器件在Ku波段（12-18 GHz）具有宽频性能,且能够在自由空间实现电磁波的可控传播。研究验证了利用3D打印技术进行人工电磁介质器件制造的可行性,为其进一步推广应用奠定了基础。

A novel method will be proposed to realize the integrated design and fabrication of the micro- and macro- structures for the artificial electromagnetic（EM） medium driven by the physical properties of the devices. The mapping relations between feature parameters of the unit cell and the effective permittivity as well as index of the artificial medium have been established with the photonic crystal structures in metamaterial regime. Using these mapping relations, artificial EM medium with gradient index has been designed controllably. Based on the theoretical calculation, the EM wave carpet cloak and black hole are designed with the gradient index artificial medium. These complicated 3D EM devices have been fabricated by using 3D printing process with the photo-curable resin as the raw material. Experimental results show the broadband properties in the Ku frequency range（12-18 GHz） and the controllable transmission for the EM wave in the free space. The possibility to fabricate the EM devices using artificial medium has been demonstrated by the present research, and these will be the foundation for the further industrial applications of 3D printing in EM field.