Silicon Radar is a fundamental sensing modality for ADAS (Advanced Driver Assistance Systems) and automotive safety applications. The growing number of radars per vehicle requires high-performance and highly integrated semiconductors. These can support the ever-increasing operating frequencies with the lowest power consumption while satisfying the ever-increasing demand for resolution in both external and in-cabin radar systems. In this regard, the radar industry is currently moving toward 120 GHz (in-cabin sensing) and 140 GHz (external sensing). These higher frequencies enable the use of antenna-on-chip techniques, significantly raising the integration levels, and make it possible to create products with a complete radar on a chip. It vastly simplifies PCB design and dramatically reduces costs, especially for in-cabin Occupant Monitoring Systems (OMS). Furthermore, it opens significant new market areas.