System Analysis of a Phased-Array Radar Applying Adaptive Beam-Control for Future Automotive Safety Applications

In this contribution, we present a novel beam-control approach for automotive phased-array radar frontends. Since radar sensors are considered to be one of the means to enable future advanced safety functionality, we previously developed a system simulation environment that incorporates all involved domains and calculates all relevant high-level effects accurately. Subsequently, a generic phased-array FMCW radar frontend has been implemented and parameterized according to state-of-the-art SiGe components operating in the 77 GHz band. To demonstrate the advantages of an adaptively controlled beam for future safety applications, it is focused on curved traffic situations, which are calculated in a co-simulation incorporating a 3D-raytracer. A novel method for the control of the antenna characteristic is derived, which takes the specific curve geometry into account, and predictive enhancement features applied to it are elucidated, before their utilization and the resulting increase of system performance is computed. By adaptively coupling the radar sensor to the steering angle, thus directing its beam together with the ego-vehicle into the curve, its measurement range can be distinctly increased, which is providing more time for the safety system to react. This set of facts is first examined in a static view, by regarding only some specially selected timesteps, before a thorough analysis of the complete traffic scenario reveals the system's advantages from a dynamic point-of-view. As a result, the performance improvement of phased-array frontends applying adaptive beam-control compared to those with body-fixed nonsteerable beams is proven. Moreover, some results which are to be expected from such an advanced system, in case its full potential is evolved by implementing a scanning functionality, are provided as an outlook on future developments.