Silicon Waveguide Integrated Technologies for Intelligent Millimeter-wave/Terahertz Micro-Systems

电磁波的毫米波（mmW）/太赫兹（THz）频谱（特别是0.1至3 THz）位于无线电频率和光波之间，具有两种频谱中最理想的特性。 与无线电波一样，毫米波/太赫兹波可以穿透不透明的物体，同时提供的几何分辨率仅与光波相当。这种独特的特性使超宽带通信（毫米波卫星通信，5G及更高），高分辨率雷达（未来的汽车雷达），安全成像，生物医学/制药材料表征和射电天文学中的广泛新应用成为可能。 尽管该频率范围具有独特的优势并且mmW商业（CMOS、SiGe）纳米级半导体技术取得了令人印象深刻的进步，但是缺乏具有合理性能的有效mmW/THz有源器件以及现有无源器件的成本和复杂性以及缺乏合适的集成技术平台已经阻碍了该频谱的快速工业规模使用。 虽然低成本的毫米波/太赫兹有源器件技术在大众市场应用中还有很长的路要走，但高效、低插入损耗的无源器件和天线以及低成本的集成技术可以在很大程度上弥补有源器件效率和灵敏度的不足，以及它们的噪声行为。 当前用于RF/微波频率范围的平面多层电路和天线技术不适用于mmW/THz系统，这是由于金属和普通商业级软衬底的大插入损耗。目前，用于100+ GHz波传输/处理的主流技术是金属波导及其变体，其体积大、重量重且相当昂贵，特别是在THz，几乎没有集成的可能性。这已经成为以低成本实现集成mmW/THz商业产品的主要瓶颈。 作为解决该问题的一种全新方法，申请人小组在过去8年中一直在研究和开发用于集成波传输/处理/发射的新型Si基技术平台。新的技术平台是基于硅波导在玻璃或硅基板在毫米波/太赫兹的频率范围。这项研究产生了一个成熟的技术平台和几个新的设计概念，如毫米波/太赫兹传感器和具有波束控制能力的天线阵列。 建议的研究的主要目标是调查最具成本效益的系统（电路/天线/封装）集成技术在开发的硅基平台。拟议计划的主要重点是集成有源器件，包括传统和新型器件，如石墨烯，以及开发用于新兴mmW/THz通信系统、成像和传感的模块化大规模集成智能微系统。

Sitting between the radio frequencies and light-waves, millimeter-wave (mmW)/Terahertz (THz) spectra of electromagnetic waves (particularly 0.1 to 3 THz) have the most desirable properties of both spectra. Like radio waves, mmW/THz waves can penetrate into opaque objects and, at the same time, provide geometrical resolution only comparable to that of the light-waves. Such unique characteristics have enabled a wide range of new applications in ultra-broadband communication (mmW satellite communication, 5G and beyond), high resolution radar (future automotive radars), security imaging, biomedical/pharmaceutical material characterizations, and radio astronomy. Despite unique advantages of this range of frequencies and impressive advances in mmW commercial (CMOS, SiGe) nano-scale semiconductor technologies, lack of efficient mmW/THz active devices with reasonable performance, as well as the cost and complexity of the existing passive devices and the lack of a suitable integration technology platform has hindered fast industrial scale usage of this spectrum. Although there is still a long way to low-cost mmW/THz active device technologies for mass market applications, highly efficient and low insertion loss passive devices and antenna and low-cost integration technologies can, to a large extent, compensate for the active devices lack of efficiency and sensitivity, as well as their noisy behavior. Current planar multi-layer circuit and antenna technologies for RF/microwave range of frequencies are not applicable to mmW/THz systems due the large insertion loss of metals and common commercial grade soft substrates. Currently, the mainstream technique for wave transmission/processing at 100+ GHz is metallic waveguide and its variations, which are bulky, heavy, and quite costly, particularly at THz, with almost no possibility of integration. This has become a major bottleneck for realizing integrated mmW/THz commercial products at low cost. As a fundamentally new approach to this problem, the applicant group has been investigating and developing a novel Si-based technology platform for integrated wave transmission/processing/emission, over the past 8 years. The new technology platform is based on Si-waveguide on glass or Si substrate at mmW/THz range of frequencies. This research has resulted in a proven technology platform and several novel design concepts such as mmW/THz sensors and antenna arrays with beam control capability. The main objective of the proposed research is to investigate the most cost-effective system (circuit/antenna/package) integration technologies in the developed Si-based platform. Major foci in the proposed program are integration of the active devices, both conventional and new ones such as graphene and development of modular large scale integrated intelligent microsystems for emerging mmW/THz communication systems, imaging, and sensing.