Radar apparatus
View Patent ↗A transmitting array antenna includes a second antenna group placed in a position inside a first antenna group in a first direction and a position different from the first antenna group in a second direction. A receiving array antenna includes a fourth antenna placed in a position outside a third antenna group arranged in the first direction and a position different from the third antenna group in the second direction. An interelement spacing between a receiving antenna of the third antenna group located at an end on a second side is identical to an interelement spacing in the first direction between a transmitting antenna of the first antenna group on the first side and each of the second antenna group. In a case where the first antenna group and the third antenna group are identical in position in the second direction, positions of antennas are different.
1. A radar apparatus comprising:
a radar transmitter that transmits a radar signal through a transmitting array antenna; and
a radar receiver that receives, through a receiving array antenna, a reflected-wave signal produced by the radar signal being reflected by a target,
wherein the transmitting array antenna is composed of a first antenna group including a plurality of transmitting antennas arranged in a first direction and a second antenna group including at least one transmitting antenna placed in a position inside at least one pair of adjacent transmitting antennas of the first antenna group in the first direction and a position different from the first antenna group in a second direction orthogonal to the first direction,
the receiving array antenna is composed of a third antenna group including a plurality of receiving antennas arranged in the first direction and a fourth antenna that is one receiving antenna placed in a position outside an end of the third antenna group in the first direction and a position different from the third antenna group in the second direction,
an interelement spacing between the adjacent transmitting antennas in the first direction is a sum of an aperture length of the third antenna group and a spacing between the third antenna group and the fourth antenna in the first direction,
one or more interelement spacings in the first direction, from a receiving antenna of the third antenna group located at an end on a second side opposite to a first side on which the fourth antenna is placed, to one or more of the other receiving antenna(s) of the third antenna group, equal one or more interelement spacings in the first direction, from a transmitting antenna of the first antenna group located at an end on the first side, to one or more of the transmitting antenna(s) of the second antenna group, and
spacing (D TV ) between the first antenna group and the second antenna group in the second direction is different from a spacing (D RV ) between the third antenna group and the fourth antenna in the second direction.
2. The radar apparatus according to claim 1 , wherein interelement spacings between the plurality of receiving antennas of the third antenna group are equal.
3. The radar apparatus according to claim 1 , wherein interelement spacings between the plurality of receiving antennas of the third antenna group and a spacing between the third antenna group and the fourth antenna in the first direction are equal.
4. The radar apparatus according to claim 1 , wherein interelement spacings between the plurality of receiving antennas of the third antenna group are different.
5. The radar apparatus according to claim 1 , wherein interelement spacings between the plurality of receiving antennas of the third antenna group and a spacing between the third antenna group and the fourth antenna in the first direction are different.
6. The radar apparatus according to claim 1 , wherein D TV =2D RV or 2D TV =D RV .
7. The radar apparatus according to claim 1 , wherein D TV ≠2D RV and 2D TV ≠D RV .
8. The radar apparatus according to claim 1 , wherein the second antenna group includes n (an integer of not less than 1) transmitting antennas, and
the third antenna group includes at least (n+1) receiving antennas.
9. The radar apparatus according to claim 1 , at least one of the transmitting and receiving antennas is constituted by a plurality of sub-array elements arranged in the second direction.
10. A radar apparatus comprising:
a radar transmitter that transmits a radar signal through a transmitting array antenna; and
a radar receiver that receives, through a receiving array antenna, a reflected-wave signal produced by the radar signal being reflected by a target,
wherein one of the transmitting array antenna and the receiving array antenna includes a first antenna group including a plurality of antennas arranged in a first direction and a second antenna group including a plurality of antennas, each arranged at a position different from that of each of the plurality of antennas of the first antenna group in the first direction and a second direction orthogonal to the first direction,
wherein another one of the transmitting array antenna and the receiving array antenna includes a third antenna group including a plurality of antennas arranged in the first direction and a fourth antenna that is one antenna located outside an end of the third antenna group in the first direction and at a position different from the third antenna group in the second direction,
wherein the first antenna group is arranged inside one pair of adjacent antennas of the second antenna group in the second direction.