Evaluation of Design Considerations for Radome Heating Foils in Automotive Radars

Snow and ice layers can lead to functional impairments or unavailability of radar sensors, which are of particular concern to advanced driver assistance systems (ADAS) and autonomous driving (AD). This article discusses the evaluation of heating foils which are employed for the removal of snow and ice layers on radomes of automotive radars. Heating foils are made of wire grids embedded into a dielectric foil material, which is then integrated into bumpers or design-emblems. A comprehensive study of the transmission properties of the heating foils for the frequency range of 76 to 81 GHz is presented using analytical, simulative, and experimental approaches. A transmission measurement setup based on the quasi-optical technique was implemented to assess the transmission through the heating foils. As a result of this study, recommendations are made on the wire spacing that ensures minimum attenuation to the radar signals.