Patent ID: 8842262

Claim:
A radar apparatus for detecting a distance to an object by receiving an electromagnetic wave reflected by the object, the radar apparatus comprising: a scan part including a polarized light separation member configured to pass a preset first component of the electromagnetic wave and reflect a preset second component of the electromagnetic wave, wherein the first and second components, respectively, are polarized lights having first and second polarization directions, which are perpendicular to each other, wherein the scan part scans the second component of the electromagnetic wave in a predetermine scan angle range by rotating the polarized light separation member around a predetermined rotation axis; an electromagnetic wave emitter configured to emit the electromagnetic wave toward the polarized light separation member of the scan part, an electromagnetic wave detector disposed on an opposite side of the polarized light separation member from the electromagnetic wave emitter so that the electromagnetic wave detector detects the electromagnetic wave that has emitted from the electromagnetic wave emitter toward the polarized light separation member and thereafter has transmitted through the polarized light separation member; and a conversion reflector disposed on an opposite side of the polarized light separation member from a scan passage region, wherein: the conversion reflector reflects the electromagnetic wave that has traveled from the scan passage region to the polarized light separation member and thereafter has transmitted through the polarized light separation member; the scan passage region is a region through which the electromagnetic wave scanned by the scan part passes; and the conversion reflector reflects the incident electromagnetic wave in a direction opposite to an incident direction while converting a direction of polarization of the electromagnetic wave into the second polarization direction.