Patent attributes
In a radar apparatus, a radar device emits a transmission wave to a periphery of a vehicle and detects a reflected wave of the transmission wave through a window part. As a member for restricting or reducing adhesion of dirt and foreign materials to the window part, an air duct is provided to apply air toward the window part. An air outlet portion of the air duct is open at a periphery of the window part and has a passage area smaller than that of an air inlet portion, which opens to a vehicle forward direction. While the vehicle is running, air is blown from the air outlet portion to flow along the window part at high speed after its pressure is increased in the air duct. Thus, dirt and materials adhering or adhered to the window part is effectively blown off.