Millimeter wave-radar and method for manufacturing the same

• US 7,126,525 B2
• Filed: 02/24/2004
• Issued: 10/24/2006
• Est. Priority Date: 03/24/2003
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi Car Engineering Company Limited (Hitachi, Ltd.), Hitachi, Ltd.
• Inventors: Takano, Kazuaki, Suzuki, Mitsushige
• Primary Examiner(s): Tarcza, Thomas H.
• Assistant Examiner(s): ALSOMIRI, ISAM A
• Application Number:
  US10/784,882
• Publication Number:
  US 20040227663A1
• Time in Patent Office: 973 Days
• Field of Search: 342 1- 4, 342 70- 74, 342/175
• US Class Current: 342/70
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/93275 in the bumper area
• CPC Class Codes: G01S 7/03 Details of HF subsystems specially adapted therefor, e.g. common to transmitter and receiver
• CPC Class Codes: G01S 7/2813 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 1/42 Housings not intimately mechanically associated with radiating elements, e.g. radome
• CPC Class Codes: H01Q 17/001 for modifying the directional characteristic of an aerial

Abstract

A millimeter-wave radar has a radome or radar cover including a layer, the dielectric constant of which is a greater than that of the other portion without the layer, or including a magnetic loss layer in an appropriate position with respect to the antenna. The dielectric constant of the radome or radar cover can be made higher in a portion corresponding to the side of the antenna than in a portion corresponding to the front of the antenna.

Claims

1. A millimeter wave-radar comprising:

an antenna base having a transmission/reception antenna;

a housing fixing the antenna base; and

at least a radome or a radar cover enclosing the antenna base;

wherein the radome or the radar cover has a dielectric constant which progressively increases from a front of the transmission/reception antenna toward a side of the antenna.

2. A millimeter wave-radar according to claim 1 wherein a radio wave absorbing layer is provided to a side surface of the radome or the radar cover.

3. A millimeter wave-radar according to claim 1 wherein the radome or the radar cover is provided with a radio wave absorbing layer having its performance adjusted according to its position with respect to the transmission/reception antenna.

4. A millimeter wave-radar according to claim 1 wherein the radome or the radar cover is provided with a radio wave absorbing layer having a higher dielectric loss than that of a material of the radome or the radar cover.

5. A millimeter wave-radar according to claim 1 wherein the radome or the radar cover is provided with a radio wave absorbing layer that is a magnetic loss layer.

6. A millimeter wave-radar according to claim 1 wherein the radome or the radar cover is provided with a radio wave absorbing layer having a higher dielectric constant than that of a material of the radome or the radar cover.

7. A millimeter wave-radar according to claim 1 wherein the radome and the radar cover use a material with a dielectric constant of 3.0 or lower in a portion thereof corresponding to a front of the transmission/reception antenna.

8. A millimeter wave-radar according to claim 1 wherein the radome and the radar cover use, as a main ingredient in a portion thereof corresponding to a front of the transmission/reception antenna, at least one of polycarbonate, syndiotactic polystyrene, polypropylene and a combination of these materials as a main ingredient and acrylonitrile butadiene styrene (ABS).

9. A millimeter wave-radar according to claim 1 wherein the radome or the radar cover is provided with a radio wave absorbing layer formed of only a layer having a predetermined angle to a surface of the transmission/reception antenna or of a combination of the layer having the predetermined angle and a layer having a predetermined angle to a normal of the surface of the transmission/reception antenna.

10. A millimeter wave-radar according to claim 1 wherein the radome or the radar cover is provided with a radio wave absorbing layer is a mesh of less than ¼

of wavelength.

11. A millimeter wave-radar comprising:

an antenna base having a transmission/reception antenna;

a housing fixing the antenna base; and

at least a radome or a radar cover enclosing the antenna base;

wherein the radome or the radar cover is provided with a radio wave absorbing layer formed through an insert molding process or a double molding process; and

wherein the radome or the radar cover has a greater dielectric constant in a portion thereof corresponding to a side of the transmission/reception antenna than in a portion thereof corresponding to a front of the antenna.

12. A millimeter wave-radar according to claim 11, wherein the radome and the radar cover use in a portion thereof corresponding to a front of the transmission/reception antenna a material with a dielectric constant of 3.0 or lower.

13. A millimeter wave-radar according to claim 11, wherein the radome and the radar cover use, as a main ingredient in a portion thereof corresponding to a front of the transmission/reception antenna, at least one of polycarbonate, syndiotactic polystyrene, polypropylene and a combination of these materials as a main ingredient and ABS.

14. A millimeter wave-radar comprising:

an antenna base having a transmission/reception antenna;

a housing fixing the antenna base; and

at least a radome or a radar cover enclosing the antenna base;

wherein the radome or the radar cover has a dielectric constant which progressively increases from a front of the transmission/reception antenna toward a side of the antenna, and wherein the radome and the radar cover use in a portion thereof corresponding to a front of the transmission/reception antenna a material with a dielectric constant of 3.0 or lower.

15. A millimeter wave-radar comprising:

an antenna base having a transmission/reception antenna;

a housing fixing the antenna base; and

at least a radome or a radar cover enclosing the antenna base;

wherein the radome or the radar cover has a dielectric constant which progressively increases from a front of the transmission/reception antenna toward a side of the antenna, and wherein the radome and the radar cover use, as a main ingredient in a portion thereof corresponding to a front of the transmission/reception antenna, at least one of polycarbonate, syndiotactic polystyrene, polypropylene and a combination of these materials as a main ingredient and acrylonitrile butadiene styrene (ABS).

16. A millimeter wave-radar comprising:

an antenna base having a transmission/reception antenna;

a housing fixing the antenna base; and

at least a radome or a radar cover having an electronic permeability which progressively decreases from a front of the transmission/reception antenna toward a side of the antenna.