Fig. 1: Concept of microwave-transparent heaters for automotive radars.
From: Microwave-transparent metallic metamaterials for autonomous driving safety
a Schematic illustrating various types of sensors installed on an autonomous vehicle. b Schematics illustrating a radar sensor module with and without a heater in adverse weather conditions. A thin layer of frost or ice accumulated on the cover of the module considerably reflects or scatters both incoming and outgoing signals. c Measured and simulated S21 spectra of an uncoated glass cover within the W band. (Inset) Schematic of the measurement setup. d Schematics illustrating the principle of a microwave-transparent metamaterial. (Left) An uncoated glass substrate fails to meet the standing wave condition at a target frequency (fo) owing to its inappropriate thickness, resulting in diminished transmission at fo. (Right) A metamaterial inducing an appropriate phase delay adjusts the standing wave condition to f0, enabling perfect transmission at fo.
