Structure and technique for antenna decoupling in a vehicle mounted sensor

• US 9,653,796 B2
• Filed: 12/16/2013
• Issued: 05/16/2017
• Est. Priority Date: 12/16/2013
• Status: Active Grant

• Current Assignee: Valeo Radar Systems, Inc. (Valeo SE)
• Original Assignee: Valeo Radar Systems, Inc. (Valeo SE)
• Inventors: Pleva, Joseph S.
• Primary Examiner(s): Levi, Dameon E
• Assistant Examiner(s): Davis, Walter
• Application Number:
  US14/107,189
• Publication Number:
  US 20150171511A1
• Time in Patent Office: 1,247 Days
• Field of Search: 343841
• CPC Class Codes: G01S 13/931 of land vehicles
• CPC Class Codes: G01S 2013/9327 Sensor installation details
• CPC Class Codes: G01S 7/027 Constructional details of housings, e.g. form, type, material or ruggedness
• 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 1/526 Electromagnetic shields
• 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 21/0006 Particular feeding systems
• CPC Class Codes: H01Q 9/0407 Substantially flat resonant element parallel to ground plane, e.g. patch antenna dipole H01Q9/285; monopole H01Q9/40

Abstract

Presently disclosed is a structure and technique for de-coupling a sensor (such as an automotive radar sensor), from a surrounding electrically conductive structure (such as a vehicle) on which the sensor is mounted.

Claims

1. A radar sensor comprising:

a housing having an radome forming one face thereof;

an antenna printed circuit board (PCB) disposed in the housing;

an antenna, disposed on the antenna PCB and positioned to radiate through the radome face of the housing; and

a radio frequency (RF) absorbing frame disposed internal to the sensor housing and disposed on at least a portion of the perimeter the antenna PCB on the same surface of the antenna PCB as the antenna, said RF absorbing frame having a wedge-shaped portion proximate the antenna.

2. The radar sensor of claim 1 wherein the wedge-shaped RF absorbing frame is disposed such that RF energy from the antenna is absorbed along the surface of the antenna to reduce coupling to conductive elements external to the sensor.

3. The radar sensor of claim 1 wherein the wedge-shaped portion of the RF absorbing frame is arranged such that a thin edge of the wedge-shaped portion is proximate the antenna and a thick edge of the wedge-shaped portion is distal the antenna.

4. The radar sensor of claim 3 wherein the wedge-shaped portion of the RF absorbing frame is disposed such that RF energy from the antenna is absorbed by the wedge-shaped portion of the frame along the surface of the antenna to reduce coupling from the antenna to conductive elements external to the sensor.

5. The radar sensor of claim 1 wherein the antenna is provided from an array of antenna elements.

6. The radar sensor of claim 5 wherein the antenna elements are provided as a dual element radiator.

7. The radar sensor of claim 6 wherein the dual element radiator comprises:

a primary patch radiator; and

a secondary patch radiator coupled to the primary patch radiator wherein the secondary patch radiator is provided having dimensions which are smaller than the dimensions of the primary patch radiator.

8. The radar sensor of claim 7 wherein the primary patch radiator is coupled to the secondary patch radiator via a transmission line.

9. A radar sensor comprising:

a housing having a radome forming one face thereof;

an antenna printed ciruit board (PCB) disposed in the housing;

an antenna disposed on the antenna PCB and positioned to radiate through the radome face of the housing; and

a radio frequency (RF) absorbing frame disposed internal to the sensor housing and disposed on at least a portion of the perimeter the antenna PCB on the same surface of the antenna PCB as the antenna, said RF absorbing frame having a wedge-shaped portion proximate the antenna wherein some portions of the RF absorbing frame have a wedge-shape while other portions of the RF absorbing frame do not have a wedge-shape and wherein the wedge-shaped portion of the RF absorbing frame is arranged such that a thin edge of the wedge-shaped portion is proximate the antenna and a thick edge of the wedge-shaped portion is distal to the antenna.

10. The radar sensor of claim 9 wherein some portions of the frame have a first wedge-shape while other portions of the frame have a second, different wedge-shape.

11. The radar sensor of claim 9 wherein the frame is disposed over the antenna PCB and secures said clamps the antenna PCB to the housing.

12. A radar sensor comprising:

a housing having an radome forming one face thereof;

an antenna printed circuit board (PCB) disposed in the housing;

an antenna, disposed on the antenna PCB and positioned to radiate through the radome face of the housing; and

a first wedge-shaped (RF) absorbing element disposed on at least a portion of the antenna PCB on the same surface of the antenna PCB as the antenna and proximate to the antenna such that RF energy from the antenna is absorbed along the surface of the antenna to reduce coupling from the antenna to conductive elements external to the sensor wherein some portions of the RF absorbing frame have a wedge-shape while other portions of the RF absorbing element do not have a wedge-shape and wherein the wedge-shaped portion of the RF absorbing element is arranged such that a thin edge of the wedge-shaped portion is proximate the antenna and a thick edge of the wedge-shaped portion is distal the antenna.

13. The radar sensor of claim 12 wherein the wedge-shaped portion of the RF absorbing frame is disposed such that RF energy from the antenna is absorbed by the wedge-shaped portion of the frame along the surface of the antenna to reduce coupling from the antenna to conductive elements external to the sensor.

14. The radar sensor of claim 12 further comprising a second wedge-shaped (RF) absorbing element disposed on at least a portion of the antenna PCB on the same surface of the antenna PCB as the antenna and proximate to the antenna such that RF energy from the antenna is absorbed along the surface of the antenna to reduce coupling from the antenna to conductive elements external to the sensor.

15. The radar sensor of claim 14 wherein the first wedge-shaped (RF) absorbing element is disposed on a first side of the antenna and the second wedge-shaped (RF) absorbing element is disposed on a second side of the antenna.

16. The radar sensor of claim 15 wherein the antenna is provided as an array antenna comprising antenna elements provided as a dual element radiators.

17. The radar sensor of claim 16 wherein the dual element radiator comprises:

a primary patch radiator; and

a secondary patch radiator coupled to the primary patch radiator wherein the secondary patch radiator is provided having dimensions which are smaller than the dimensions of the primary patch radiator.

18. The radar sensor of claim 17 wherein the primary patch radiator is coupled to the a secondary patch radiator via a transmission line.