Integration of a 77GHz automotive radar system into plastic surfaces using MID-technology

Abstract:
Novel and innovative technologies like automated and autonomous driving will provide solutions to pressing global issues related to traffic. Autonomous cars will contribute by optimizing traffic flows, resulting in a more efficient use of energy resources and infrastructure. In addition, they ensure better traffic regulation, which results in fewer casualties and more safety. To maintain a leading position in this sector, European car manufacturers must adapt to the needs of the changing market by addressing key technical challenges around autonomous driving. Radar systems are a basic prerequisite for automated and autonomous driving. However, the amount of radar sensors per car must increase from one to about ten in the future to allow for full autonomy. This, in turn, demands very cost-effective solutions without compromising on their performance. Moreover, these sensors must be easily integrable in the car exterior, yet invisible to the eye of the customer. The alignment within the vehicle must be precise while the replacement shall be possible without significant effort. To address this need, new manufacturing technologies, materials and different integration strategies are required in the vehicle. The integration challenges in this application area of automotive radar are to be enabled by applying 3D-MID technology. 3D-MID is a packaging and integration technology that allows for three-dimensional arrangements of components and great flexibility in the shape of the final module. In the past years it has matured from a pure research topic towards high technology readiness levels (TRLs) and is already explored and adopted in many domains. Also, for the automotive sector 3D-MID is a promising solution. However, the usually rather conservative European car industry has not yet started to explore its possibilities, even though Europe is home to some of the word-leading companies and research organisations in this area. Therefore, the project MID4automotive is aiming to bridge the gap between the car manufac-turers on one hand and the 3D-MID companies and experts on the other hand to help both industries to maintain and expand their leadership in their areas. The targeted innovation in this project is the adaptation of the technology towards its use in wireless automotive modules through the development of a radar sensor in 3D-MID technology that is directly integrated into the bumper of a car. This module aims to surpass the angular resolution of state-of-the-art radar modules by a factor of six. Moreover, the integration of bare-dies into 3D-MID technology as well the integration of fibre-optic components to allow for low-loss interconnections of multiple radar sensors are targeted innovations in this project. Radar systems that cover the entire surroundings of a vehicle are a basic prerequisite for autonomous driving. Due to their current design, the installation of the radar systems is difficult. Particularly in the side and rear areas, space to mount these radar modules is not available. Furthermore, these modules are very complex in their mechanical construction, which increases the costs. The installation also requires mounting fixtures on the vehicle, which leads to a costly assembly and adjustment. Moreover, the bumper has a negative effect on the detection quality and accuracy due to scattering and refraction of the radar signals. Finally, as a crucial performance criterium for autonomous driving, the angular domain in both elevation and azimuth needs to be improved creating so called imaging radars. This could be achieved by larger antenna arrays or coherent processing over multiple antenna front-ends distributed over the car.