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

位于无线电频率和光波之间，毫米波(mmW)/太赫兹（THz）电磁波频谱（特别是0.1到3太赫兹）具有两种频谱最理想的特性。像无线电波一样，毫米波/太赫兹波可以穿透不透明的物体，同时提供与光波相当的几何分辨率。这种独特的特性使超宽带通信（毫米波卫星通信、5G及以上）、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等领域的广泛新应用成为可能。

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.