Emerging Trends in Radar: Silicon-Based THz MIMO Systems

Multiple-input and multiple-output (MIMO) radar systems are an active field of research, indicated by progress in all domains, such as circuit and monolithic microwave integrated circuit (MMIC) design, as well as systems and algorithms. While the 61-GHz ISM and the 77-GHz automotive bands are predominantly used in many applications, some applications emerge into the D-band and still prefer silicon to III/V technologies. This article highlights the state of the art of THz MIMO radar systems beyond D-band. While high-power signal generation in the THz range is limited by the technology, large arrays seem to be a key enabler of THz systems. Moreover, radar cross sections and on-chip antenna efficiency benefit from the smaller wavelength. Lastly, this article highlights the key challenges for future research, including frequency-scaling effects of components and transmit power as well as system dynamic range, and shows what is needed for THz systems using today's silicon technologies.