Integrated and Programmable Chip-Scale millimeter-wave and Terahertz systems for Communication, Sensing, and Imaging

Abstract

Millimeter-wave(mm-wave) and Terahertz(THz) technologies have shown applications ranging from high-speed wireless communications to biomedical imaging. However, despite the significant efforts in this part of the electromagnetic spectrum, efficient devices and systems with reasonable DC-to-RF efficiencies and programmability are lacking. In this dissertation, the design and implementation of THz and mm-Wave devices and systems are explored by mitigating fundamental challenges through architectural innovations in EM-Circuit co-design. To highlight some of my works, I have experimentally demonstrated for the first time: silicon-based THz power generation capability; THz wireless-link localization; THz/mm-wave intelligent reconfigurable surfaces for improved and efficient wireless communication; and mm-wave dynamically reconfigurable element-level pattern synthesis to generate optimal patterns in the presence of near-field interferers. These systems could play a critical role in the next generation of high-speed communication links, high-resolution imaging, and sensing applications. In the silicon-based THz power-generation work, a new method of creating time-synchronization across THz oscillator arrays is proposed, establishing a robust frequency and phase distribution across the entire chip for high-power THz generation. The 4x4 scalable array has been demonstrated with the highest reported radiated power in this frequency range. In the THz wireless-link localization work, we overcome the inefficient, iterative-based node detection techniques with a novel spectrum-to-space mapping principle, leading to fast, one-shot, multi-node localization and link discovery. The transmissive and reflective reconfigurable surfaces operating in both mm-Wave and THz frequencies were demonstrated, which can be a part of large-scale high-speed wireless link systems. The THz transmissive, reconfigurable holographic surface can control the wavefront’s shape, which is valuable in applications including wireless communication, sensing, and imaging. The mm-Wave active, intelligent reflecting surfaces (IRS) allow reconfiguring the channel on demand and creating programmable non-line-of-sight (NLOS) paths. Such scalable solutions are critical for the densification of base stations and access points. Finally, the proposed element-level pattern reconfigurability can facilitate real-time programming to mitigate the impact of near-field perturbations for smaller-sized arrays at the user equipment. In chapter 7, I conclude my research and the systems we explored and demonstrated in this dissertation are further extended to various innovative ideas under the EM-circuit co-design.