公开(公告)号：US20190302226A1

公开(公告)日：2019-10-03

申请号：US16303935

申请日：2017-05-17

Applicant: DENSO CORPORATION

Inventor： Toshiya SAKAI ,  Kazumasa SAKURAI ,  Kazushi KAWAGUCHI ,  Takuya KOYA

IPC: G01S7/03 ,  H01Q1/32 ,  H01Q1/42

Abstract: A radar apparatus includes an antenna unit and a cover unit. The cover unit is arranged at a position through which an electromagnetic wave sent and received by the antenna unit passes. The cover unit has, in an order from closer to the antenna unit, a first dielectric layer formed of a dielectric and a second dielectric layer formed of a dielectric having a dielectric constant different from that of the first dielectric layer. The first dielectric layer is configured to have a thickness not more than that for a maximum external transmittance. The external transmittance indicates a transmittance of an electromagnetic wave, which is emitted in a direction of an incidence angle with respect to the first dielectric layer, which is equal to a maximum sensing angle, when the electromagnetic wave is transmitted through the cover unit.