Automotive Radar

• US 20070241962A1
• Filed: 11/14/2003
• Published: 10/18/2007
• Est. Priority Date: 11/14/2003
• Status: Abandoned Application

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Shinoda, Hiroshi, Kondou, Hiroshi
• Application Number:
  US10/578,768
• Publication Number:
  US 20070241962A1
• Time in Patent Office: Days
• US Class Current: 342/361
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/9321 Velocity regulation, e.g. cruise control
• CPC Class Codes: G01S 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 7/024 using polarisation effects in waveguides H01P1/165; for aerials H01Q, e.g. H01Q15/22, H01Q15/24, H01Q19/195
• CPC Class Codes: G01S 7/027 Constructional details of housings, e.g. form, type, material or ruggedness
• CPC Class Codes: G01S 7/032 Constructional details for solid-state radar subsystems
• CPC Class Codes: G01S 7/2813 Means providing a modification of the radiation pattern for cancelling noise, clutter or interfering signals, e.g. side lobe suppression, side lobe blanking, null-steering arrays specially adapted to secondary radar systems G01S13/762; aerials or aerials systems H01Q21/29, H01Q25/00
• 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 1/425 comprising a metallic grid
• CPC Class Codes: H01Q 1/52 Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure absorbing means H01Q17/00
• CPC Class Codes: H01Q 15/0013 said selective devices working as frequency-selective reflecting surfaces, e.g. FSS, dichroic plates, surfaces being partly transmissive and reflective
• CPC Class Codes: H01Q 15/24 Polarising devices; Polarisation filters H01Q15/12, H01Q15/22 take precedence
• CPC Class Codes: H01Q 17/00 Devices for absorbing waves radiated from an antenna; Combinations of such devices with active antenna elements or systems
• CPC Class Codes: H01Q 17/001 for modifying the directional characteristic of an aerial
• CPC Class Codes: H01Q 19/028 for reducing the cross polarisation
• CPC Class Codes: H01Q 19/28 using a secondary device in the form of two or more substantially straight conductive elements log- periodic antennas H01Q11/10; constituting a reflecting surface H01Q19/10
• CPC Class Codes: H01Q 21/065 Patch antenna array
• CPC Class Codes: H04L 27/26265 Arrangements for sidelobes suppression specially adapted to multicarrier systems, e.g. spectral precoding

Abstract

A small and light automotive radar having a high detection performance by preventing the road clutter and its in-vehicle positioning is optional is provided. The automotive radar comprises an antenna 1, 2a, 2b equipped with at least one radiating element which radiates linear polarized radio waves; a slit plate 7 which is a metal plate in which a plurality of slits are defined, placed in front of the surface of the antenna; radio wave absorbers 5 provided between the antenna and the slit plate; and a transceiver device which supplies transmit signals to the antenna to radiate radio waves and, from signals acquired by receiving reflection waves which are returned waves of the radio waves reflected by an obstruction, detects a direction in which the obstruction exists.

Claims

1. An automotive radar comprising:

an antenna equipped with at least one radiating element which radiates linear polarized radio waves;

a slit plate which is a metal plate in which a plurality of slits are defined, placed in front of the surface of the antenna;

radio wave absorbers provided between the antenna and the slit plate; and

a transceiver device which supplies transmit signals to the antenna to radiate radio waves and, from signals acquired by receiving reflection waves which are returned waves of the radio waves striking an obstruction, detects a direction in which the obstruction exists.

2. The automotive radar according to claim 1, wherein the longitudinal direction of the slits defined in the slit plate is orthogonal to the direction of co-polarized waves being radiated from the radiating element.

3. The automotive radar according to claim 1, wherein a distance between the antenna and the slit plate falls within a range from one-eighth to one-half of an effective wavelength at a frequency used by the radar.

4. The automotive radar according to claim 1, wherein the radio wave absorbers are placed between edges of the antenna and edges of the slit plate to block at least unwanted radiation in a top and bottom direction when the radar is mounted on a mobile object.

5. The automotive radar according to claim 1, wherein the radio wave absorbers are placed between edges of the antenna and edges of the slit plate to block at least unwanted radiation in a horizontal direction when the radar is mounted on a mobile object.

6. The automotive radar according to claim 1, further comprising a radome made of a dielectric material, wherein the antenna and the slit plate are covered by the radome.

7. The automotive radar according to claim 6, wherein at least one surface of the slit plate is brought in contact with the radome.

8. The automotive radar according to claim 6, wherein a distance between the radome and the antenna is larger than a distance between the slit plate and the antenna.

9. An automotive radar comprising:

an antenna which radiates linear polarized radio waves in a forward direction;

a slit plate which is a metal plate in which a plurality of slits are defined, placed in front of the antenna;

radio wave absorbers provided between the antenna and the slit plate to absorb radio waves being radiated in a direction orthogonal to a forward direction of the antenna; and

a transceiver device which supplies transmit signals to the antenna to radiate radio waves and, from signals acquired by receiving reflection waves which are returned waves of the radio waves reflected by an obstruction, detects a direction in which the obstruction exists.

10. The automotive radar according to claim 9, wherein the radio wave absorbers are placed between edges of the antenna and edges of the slit plate to block at least unwanted radiation in a top and bottom direction when the radar is mounted on a mobile object.