Radar apparatus

• US 10,230,176 B2
• Filed: 05/08/2014
• Issued: 03/12/2019
• Est. Priority Date: 05/08/2013
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Natsume, Kazuma
• Primary Examiner(s): Windrich, Marcus E
• Application Number:
  US14/889,827
• Publication Number:
  US 20160104946A1
• Time in Patent Office: 1,769 Days
• Field of Search: 342 70- 72
• CPC Class Codes: G01S 13/345 using triangular modulation
• CPC Class Codes: G01S 13/42 Simultaneous measurement of distance and other co-ordinates indirect measurement G01S13/46
• CPC Class Codes: G01S 13/584 adapted for simultaneous range and velocity measurements
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 7/03 Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
• CPC Class Codes: G01S 7/35 Details of non-pulse systems
• CPC Class Codes: H01Q 1/3233 particular used as part of a sensor or in a security system, e.g. for automotive radar, navigation systems
• CPC Class Codes: H01Q 1/3258 using the gutter of the vehicle; Means for clamping a whip aerial on the edge of a part of the vehicle
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00

Abstract

A radar apparatus includes a first antenna and a second antenna. The first antenna includes a plurality of first antenna elements that are arrayed in a first direction on a surface oriented to a forward direction, as antenna elements configuring the first antenna. The second antenna includes a plurality of second antenna elements that are arrayed in a second direction perpendicular to the first direction on the surface oriented to a forward direction, as antenna elements configuring the second antenna. The radar apparatus emits radar waves in a forward direction using either of the first and second antennas, and receives reflected waves of the radar waves using the other of the first and second antennas.

Claims

1. A radar apparatus comprising:

a first antenna; and

a second antenna,

the first antenna including, as antenna elements configuring the first antenna, a plurality of first antenna elements that are arrayed in a first direction on a surface oriented in a forward direction;

the second antenna including, as antenna elements configuring the second antenna, a plurality of second antenna elements that are arrayed in a second direction perpendicular to the first direction on a surface oriented in a forward direction,

the radar apparatus emitting radar waves using either of the first antenna and the second antenna, and receiving reflected waves of the radar waves using the other of the first antenna and the second antenna, wherein;

the first antenna includes a plurality of rows of first antenna element groups in the second direction, as the plurality of first antenna elements that are arrayed in the first direction;

the first antenna is configured to include two rows of the first antenna element groups as the plurality of rows of the first antenna element groups, the plurality of first antenna elements configuring the two rows of first antenna element groups being alternately arrayed in rows in the first direction to configure a zigzag array along two directions slanted relative to the first direction, the two rows of the first antenna element groups being arranged at positions differing from each other by a predetermined distance in the second direction;

the second antenna is configured such that the plurality of second antenna elements adjacent to each other are arranged at positions in the second direction, the positions differing from each other by a distance equal to twice the predetermined distance;

the first antenna as a reception antenna that receives the reflected waves; and

the second antenna as a transmission antenna that transmits the radar waves,

the apparatus further comprising;

a transmission control means for inputting transmission signals of the radar waves to the plurality of second antenna elements such that the radar waves are emitted from the plurality of second antenna elements at differing timings, and

an azimuth detecting means for detecting an incoming azimuth of the reflected wave on the basis of a reception signal for each combination of the plurality of first antenna elements and the plurality of second antenna elements, with reception signals of each of the plurality of first antenna elements configuring the first antenna being sorted and defined for each of the plurality of second antenna elements that is a transmission source of the corresponding radar wave, and

the azimuth detecting means;

detects an incoming azimuth relative to a first slanted direction of the reflected wave or an azimuth spectrum indicating a correspondence between the incoming azimuth and a reception power, on the basis of the reception signals of a corrected group of reception points arrayed along the first slanted direction that is indicated by the zigzag array, in a collection of the corrected reception points when reception points of the plurality of first antenna elements that receive the reflected waves of the radar waves emitted from the plurality of second antenna elements are corrected in conformity with the second direction so that, assuming that the radar waves are emitted from a specific single second antenna element among the plurality of second antenna elements, a path length from an

emission point of the radar waves to each reception point, is equal to a path length when the assumption is not made;

detects an incoming azimuth relative to a second slanted direction of the reflected wave or an azimuth spectrum indicating a correspondence between the incoming azimuth and a reception power, on the basis of the reception signals of a group of corrected reception points arrayed along the second slanted direction that is indicated by the zigzag array; and

detects incoming azimuths relative to the first and second directions of the reflected waves, as the incoming azimuths of the reflected waves, on the basis of the detected incoming azimuths relative to the first and second slanted directions of the reflected waves or the azimuth spectrums.

2. The radar apparatus according to claim 1, wherein:

the azimuth detecting means;

detects, for at least a single array among corrected groups of reception points arrayed along the first slanted direction, an incoming azimuth relative to the first slanted direction of the reflected waves or an azimuth spectrum by conducting a digital beamforming process of the reception signals of the group of corrected reception points configuring the array; and

detects, for at least a single array among corrected groups of reception points arrayed along the second slanted direction an incoming azimuth relative to the second slanted direction of the reflected waves or an azimuth spectrum by conducting a digital beamforming process of the reception signals of the group of corrected reception points configuring the array.

3. The radar apparatus according to claim 1, wherein the first direction is a horizontal direction and the second direction is a vertical direction.

4. The radar apparatus according to claim 1, wherein:

the reception antenna and the transmission antenna are configured by a planar antenna mounted to a vehicle;

the planar antenna has an antenna board and a conductor pattern formed on a surface of the antenna board; and

the plurality of first antenna elements and the plurality of second antenna elements are configured by the conductor pattern formed on the surface of the antenna board.

5. The radar apparatus according to claim 4, wherein:

the azimuth detecting means has a plurality of mixers that are electrically connected to the respective plurality of first antenna elements, an analog-to-digital converter that is connected to an output side of the plurality of mixers, and a signal processing unit that is connected to an output side of the analog-to-digital converter; and

the transmission control means has a transmission circuit that is electrically connected to the plurality of second antenna elements and a distribution circuit that power-distributes transmission signals from the transmission circuit to the plurality of second antenna elements side and the plurality of mixers side.

6. The radar apparatus according to claim 1, wherein:

each of the plurality of first antenna elements configuring the plurality of rows of the first antenna element groups is configured to be elongated in the second direction, and

the first antenna is configured such that the plurality of first antenna elements configuring the plurality of rows of the first antenna element groups are alternately arranged in rows in the first direction.

7. The radar apparatus according to claim 1, wherein the first antenna is configured such that the plurality of rows of the first antenna element groups, that are adjacent to each other, are arranged at positions in the second direction differing from each other by a distance shorter than the length of the plurality of first antenna elements in the second direction.