RADAR APPARATUS

摘要

A radar apparatus of the present invention is provided with at least one horn antenna for radiating and receiving linearly-polarized radio waves. The inner circumferential surface of the horn antenna has a top surface and a bottom surface, and a right side surface and a left side surface facing each other, the top surface and the bottom surface being perpendicular to a direction of the electrical field and facing each other. The top surface and the bottom surface define a first steeply-widened portion having a first rate of a widening rate, and define a first gently-widened portion having a second rate of a widening rate, the second rate being lower than the first rate. High-order modes can be generated within the horn antenna by the first steeply-widened portion and the first gently-widened portion to reduce sidelobes in the elevation angle direction.

主权项

1. A radar apparatus, for detecting an object at a place farther than a predetermined distance, comprising:
an antenna member including at least one horn antenna that performs the radiation of linearly-polarized radio waves to the object and reception of reflected waves from the object; and a waveguide that transfers the radio waves; and at least one circuit that performs the generation of the radio waves and the processing of a signal of the reflected waves; wherein a base portion of the horn antenna and the waveguide are connected; the waveguide and the circuit are coupled; the horn antenna has a funnel shape extending from the base portion to an aperture of the horn antenna; a cross-section of the horn antenna in a plane perpendicular or substantially perpendicular to an axis of the horn antenna has a rectangular shape; the area of the cross-section gradually increases from the base portion toward the aperture; an inner circumferential surface of the horn antenna includes a top surface and a bottom surface extending from the base portion toward the aperture, and a right side surface and a left side surface connecting the top surface and the bottom surface and facing each other, the top surface and the bottom surface being perpendicular or substantially perpendicular to a direction of the electrical field of the radio waves and facing each other; the top surface and the bottom surface define a first steeply-widened portion having a first rate of a widening rate of a distance between the top surface and the bottom surface, and also define a first gently-widened portion having a second rate of a widening rate of a distance between the top surface and the bottom surface, the first gently-widened portion being positioned closer to the aperture than the first steeply-widened portion, the second rate being smaller than the first rate; the circuit performs the extraction process of the signal from the reflected waves; and the predetermined distance is greater than ten times a length measured from the base portion to the aperture.