片上集成非互易人工微波媒质及其应用研究

In this proposal, we suggest the study on physical mechanism and the potenial applications of the on-chip integrated non-reciprocal metamaterial which is constructed using semiconductor fabrication techniques. Based on the semiconductor fabrication techniques, structures with 3 orders smaller size dimension can be constructed comparing with the conventional printed-circuit board (PCB) techniques, and can be used to realize the high-density integration of passive structures and active elements. Thus, metamaterials comprised by unit cell structures which are much smaller than the wavelength of the “low” working frequency can be realized, the homogenerity of which are highly improved. By introducing active elements, like transistors, magnetized 2 dimensional electron gas (2DEG) and bianisotropic micro-structures, into each unit cell, we can break the limitations like high loss, low response speed and high complexity in high-desity integration, in conventional non-reciprocal media, and obtain the on-chip integrated non-reciprocal metamaterial which has high homogenerity and strong robustness. Using such new characteristics, high-performance microwave devices based on non-reciprocity and one-way transmission can be obtained. In this proposal, we will first analyze the unique construction solution and electromagnetic properties of the on-chip integrated non-reciprocal metamaterial, then provide relavant media theory and design method, establish appropriate simulation and experiment platform, after that, retrieve the effective constitutive parameters of the metamaterial, simulate and measure the non-reciprocal properties of the metamaterial, and achieve several application designs.

本项目致力于研究由半导体加工工艺构造的片上集成非互易人工微波媒质及其应用。采用半导体加工工艺可构造尺寸比传统印刷电路板工艺低3个数量级的微小结构，可实现无源结构与有源元件的高密度集成，能够以远小于波长的单元结构，构建工作于“较低”频率的人工媒质，从而大幅提高人工媒质的均匀性。可通过在基于半导体工艺单元结构中引入晶体管等有源元件、磁化二维电子层和双各向异性微结构，构建片上集成非互易人工微波媒质，克服传统非互易媒质在高损耗、低响应速度、高集成复杂度等方面的缺陷，并获得高均匀性、强鲁棒性等新特性，在此基础上实现高效的基于非互易和单向传输特性的微波器件。本项目将分析上述片上集成非互易人工微波媒质特有的构造方式和电磁特性，给出相关的媒质理论和设计方法，建立独特的仿真与实验平台，完成媒质等效特征参数的提取以及媒质非互易特性的仿真、测量，并进行多种应用设计。

根据研究目标，课题组进行了相应的理论、仿真和实验研究工作。在为期三年的研究中，在片上集成多模耦合谐振结构设计、非互易人工微波媒质特征参数提取、非互易有源环形器应用设计、磁化二维电子层电磁特性分析、拓扑绝缘体Weyl波色子实验观测、具有强鲁棒性的双各向异性人工微波媒质设计与单向传输应用六个方面开展工作，取得了一些有意义的研究成果。首次将光学中的时域耦合模理论应用于具有多模谐振耦合的片上集成人工微波媒质耦合单元的设计中；首次通过在片上集成微带谐振结构中引入单位增益的微波隔离器，实现了无需偏置磁场的有源环行器；与美国麻省理工科学院RLE实验室合作，首次实现了双Gyroid三维光子晶体Weyl玻色子的实验观测，相关成果发表于Science；并与杭州电子科技大学、华中科技大学、新加坡南洋理工学院和美国爱荷华州立大学合作，首次实验演示了双各向异性媒质表面支持的混合表面态具备与拓扑绝缘体相似的对几何缺陷的免疫能力。