Automotive sensor module with absorptive and/or non-reflective layer

A vehicle sensor antenna assembly, comprising:

• a metallic waveguide block defining an array of waveguide grooves;
• an antenna assembly comprising at least one antenna slot configured to receive electromagnetic radiation from the array of waveguide grooves therethrough;
• and
• an absorptive layer configured to generate a destructive interference pattern to reduce reflectivity of the electromagnetic radiation incident upon the vehicle sensor antenna assembly, wherein the antenna assembly is part of the metallic waveguide block such that the at least one antenna slot is formed within the metallic waveguide block and extends between opposite surfaces of the metallic waveguide block, wherein the metallic waveguide block comprises a recessed region, wherein the absorptive layer is positioned within the recessed region, wherein the recessed region is defined by a lip extending about a perimeter of the metallic waveguide block and elevated walls extending about the perimeter of each antenna slot of the at least one antenna slot, and wherein the recessed region comprises a height that is more than a thickness of the absorptive layer.

A vehicle RADAR module, comprising:

• a metallic waveguide block defining a waveguide groove and comprising a recessed region;
• an antenna slot at least partially aligned with the waveguide groove of the metallic waveguide block, wherein the antenna slot extends entirely through the metallic waveguide block from a first surface of the metallic waveguide block to a second surface of the metallic waveguide block opposite the first side to allow electromagnetic radiation to travel therethrough;
• an absorptive layer seated in the recessed region, the absorptive layer comprising a lossy material, wherein the absorptive layer comprises an opening at least partially aligned with the antenna slot and the waveguide groove, wherein the absorptive layer is configured to contact the metallic waveguide block to suppress surface currents on the metallic waveguide block, and wherein the absorptive layer comprises a thickness configured to suppress reflections of the electromagnetic radiation by generating destructive interference between reflections of the electromagnetic radiation above the absorptive layer with reflections of the electromagnetic radiation below the absorptive layer;
• and
• a radome layer configured to provide a weather seal to the vehicle RADAR module, wherein the radome layer is seated in the recessed region, wherein the recessed region is defined by a lip extending about a perimeter of the metallic waveguide block, and wherein the recessed region comprises a height that is more than a thickness of the absorptive layer.