Beam architecture for improving angular resolution

• US 20060145919A1
• Filed: 12/30/2004
• Published: 07/06/2006
• Est. Priority Date: 12/30/2004
• Status: Active Grant

• Current Assignee: Valeo Radar Systems, Inc. (Valeo SE)
• Original Assignee: Valeo Raytheon Systems, Inc. (Valeo SE)
• Inventors: Pleva, Joseph S., Wimmer, Wilson
• Granted Patent: US 7,248,215 B2
• Time in Patent Office: Days
• US Class Current: 342/368
• CPC Class Codes: G01S 2013/9314 Parking operations
• CPC Class Codes: G01S 2013/9315 Monitoring blind spots
• CPC Class Codes: H01Q 1/3283 side-mounted antennas, e.g. bumper-mounted, door-mounted mounted on windscreens H01Q1/1271
• 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
• CPC Class Codes: H01Q 25/002 providing at least two patterns of different beamwidth; Variable beamwidth antennas

Abstract

An automotive radar system includes a beamformer circuit and a beamcombiner circuit. The beamformer circuit forms a plurality of antenna beams at a plurality of beam ports. The beam combiner circuit receives the beams provided thereto from the beamformer circuit and combines the beams to provide a desired number of beams, with each of the beams having a desired beam shape. In one embodiment, the beamcombiner provides first and second end beams having a beamwidth which is less than a beamwidth of middle beams.

Claims

1. An antenna system for use in a vehicle radar, the antenna system comprising:

a beamformer circuit having a plurality of antenna ports and a plurality of beam ports, said beam former circuit adapted to receive an RF signal at each of the antenna ports and in response thereto, to simultaneously form a plurality of antenna beams at fixed locations in space, with each of the respective antenna beams coupled to a respective one of the beam ports; and

a beam combiner circuit adapted to receive signals from the beam ports of said beamformer circuit and to combine the signals provided thereto in such a way as to provide a resultant number of combined beams which is less than the number of beams formed by said beamformer circuit and with each of the beams having a desired beam shape.

3. The system of claim 1 wherein said beam combining circuit has a plurality of output ports with a different beam provided at each output port and wherein said beam combining circuit is operative to simultaneously provide a radio frequency signal path between at least two of the antenna ports of said beamformer circuit and one of said plurality of output ports of said beam combining circuit.

4. The system of claim 1 further comprising a beam selection circuit having a plurality of antenna beam ports and one output port, each of said antenna beam ports coupled to at least one of the plurality of outputs of said beam combiner circuit.

5. The system of claim 4 further comprising a plurality of antenna elements each of said antenna elements coupled to a corresponding one of the plurality of antenna ports of said beamformer circuit.

6. The system of claim 5 wherein said beamformer circuit forms antenna beams at fixed locations in space.

7. The system of claim 6 wherein said beamformer circuit is provided as a Butler beamforming matrix.

8. The system of claim 7 wherein said beam selection circuit comprises a plurality of switch circuits with at least a first one of said plurality of switch circuits having a common port coupled to an input port of a second one of said plurality of switch circuits.

9. The system of claim 8 said beamformer circuit, said beam combining circuit and said switch circuit are operative to simultaneously provide a radio frequency signal path between at least two of the plurality of antenna elements and the output port of said switch circuit.

10. The system of claim 1 wherein said beam combiner circuit combines beams from said beamformer circuit to provide beams having a predetermined beam shape.

11. An antenna system comprising:

a beamformer circuit having a plurality of antenna ports and a plurality of beam ports; and

a beam combiner circuit adapted to receive signals from the beam ports of said beamformer circuit and to combine the signals provided thereto in such a way as to provide one or more combined beams with each of the beams having a desired beam shape wherein said beam combiner circuit combines beams from said beamformer circuit to provide a set of antenna beams with a first end beam and a second end beam each having an antenna beamwidth which is narrower than a beamwidth of a middle beam.

2. The system of claim 11 wherein said beamformer circuit forms a plurality of antenna beams at fixed locations in space.

12. An automotive radar system comprising an antenna system which provides a set of antenna beams with a first end beam and a second end beam each having an antenna beamwidth which is narrower than a beamwidth of a middle beam.

13. The system of claim 12 wherein the antenna system comprises:

a beamformer network having a plurality of antenna ports and a plurality of network ports; and

a switched beam combiner circuit having a first plurality of ports with each one of the first plurality of ports coupled to a corresponding one of the plurality of network ports of said beamformer network and having an output port.

14. The system of claim 13 wherein the beamformer network is provided as a Butler matrix beamformer network.

15. The system of claim 14 wherein said a switched beam combiner circuit comprises a switch circuit having a plurality of switch ports coupled to the network ports of said Butler matrix beamformer network and having at least one common port and wherein said switch circuit combines beams from said Butler matrix beamformer network to proved the system having an antenna beam at a desired location.

16. The system of claim 15 wherein said switched beam combiner circuit combines beams from said Butler matrix beamformer network to provide a plurality of antenna beams with each of the antenna beams having a beamwidth selected such that on object traveling through each of the beams is detected a substantially equal number of times in each beam.

17. The system of claim 16 wherein said Butler matrix beamformer network provides sixteen beams and said switched beam combiner circuit combines said beams to provide seven antenna beams at desired locations.

18. The system of claim 17 wherein said switched beam combiner circuit combines beams from said Butler matrix beamformer network to provide five antenna beams at desired locations.

19. The system of claim 18 wherein the radar system corresponds to at least one of:

blind spot detection, lane change, park slot measurement, cross-traffic warning, pre-crash, a front parking aid, a back-up parking aid and autonomous cruise control (ACC).

20. A method of operating a radar system comprising providing a set of antenna beams with each of the antenna beams having an antenna beamwidth selected such that a first end beam and a second end beam are each provided having an antenna beamwidth which is narrower than a beamwidth of a middle beam.

21. The method of claim 20 further comprising detecting an object in each of the antenna beams.

22. The method of claim 20 wherein providing antenna beams comprises providing seven antenna beams with each of the antenna beams having an antenna beamwidth selected such that each antenna beam covers a similar amount of area in space within a given coverage zone.

23. The method of claim 20 wherein providing antenna beams comprises providing seven antenna beams.