Radar device

A radar device, comprising:

• a housing that includes an aperture in a front direction as a transmitting direction of an electromagnetic wave;
• a circuit board that is disposed in the housing such that a board surface extends along the front direction;
• an antenna unit that includes two or more antenna elements being arrayed along a direction intersecting the front direction in the circuit board, and that transmits the electromagnetic wave upward of the board surface of the circuit board and receives a reflected wave of the electromagnetic wave;
• a reflection unit that is supported in the housing above the board surface of the circuit board and that reflects the electromagnetic wave transmitted from the antenna unit to change a traveling direction of the electromagnetic wave to the front direction and reflects the reflected wave from the front direction to change a traveling direction of the reflected wave to a direction toward the antenna unit;
• and
• a dielectric lens that is disposed in the aperture of the housing to extend along a direction in which the two or more antenna elements are arrayed, and that has a semi-cylindrical shape or a parabolic-cylindrical shape projecting in the front direction.