Every year, novel RADAR-based sensing solutions are developed to manage the demand for accurate and autonomous operations in a wide range of field. An example is the automotive sector, where RADAR systems contribute to improve the driver safety. The increasing popularity of these devices imposed a change in the regulation of the spectrum band in which they can operate, pushing industries to develop RADARs in the millimeter wave band. The 76 - 81 GHz band introduces new challenges during the design stage; however, the high frequency range allows an increased available bandwidth, and it permits further system scaling. The scaling of these devices is mainly devoted to the smaller antenna dimension and the monolithic implementation of the RADAR sub-system integrated in a single chip which enable the creation of compact products.