Methods and apparatus for automotive radar sensors

• US 20050156780A1
• Filed: 01/14/2005
• Published: 07/21/2005
• Est. Priority Date: 01/16/2004
• Status: Abandoned Application

• Current Assignee: GHZ TR Corporation
• Original Assignee: GHZ TR Corporation
• Inventors: Bonthron, Andrew J., Juskovic, Gerald
• Application Number:
  US11/036,318
• Publication Number:
  US 20050156780A1
• Time in Patent Office: Days
• US Class Current: 342/107
• CPC Class Codes: G01S 13/0209 Systems with very large relative bandwidth, i.e. larger than 10 %, e.g. baseband, pulse, carrier-free, ultrawideband
• CPC Class Codes: G01S 13/343 using sawtooth modulation
• CPC Class Codes: G01S 13/347 using more than one modulation frequency
• CPC Class Codes: G01S 13/348 using square or rectangular modulation, e.g. diplex radar for ranging over short distances
• CPC Class Codes: G01S 13/4445 amplitude comparisons monopulse, i.e. comparing the echo signals received by an antenna arrangement with overlapping squinted beams
• CPC Class Codes: G01S 13/4454 phase comparisons monopulse, i.e. comparing the echo signals received by an interferometric antenna arrangement
• 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 2013/93271 in the front of the vehicles
• CPC Class Codes: G01S 2013/93272 in the back of the vehicles
• CPC Class Codes: G01S 2013/93274 on the side of the vehicles
• CPC Class Codes: G01S 3/32 derived from different combinations of signals from separate antennas, e.g. comparing sum with difference
• CPC Class Codes: G01S 3/48 the waves arriving at the antennas being continuous or intermittent and the phase difference of signals derived therefrom being measured
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/16227 the bump connector connecting to a bond pad of the item
• CPC Class Codes: H01L 2224/32225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 2224/45014 Ribbon connectors, e.g. rectangular cross-section
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 : Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48091 : Arched
• CPC Class Codes: H01L 2224/48227 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/73204 : the bump connector being embedded into the layer connector
• CPC Class Codes: H01L 2224/73253 : Bump and layer connectors
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/15311 : being a ball array, e.g. BGA
• CPC Class Codes: H01L 2924/15313 : being a land array, e.g. LGA
• CPC Class Codes: H01L 2924/16251 : Connecting to an item not being a semiconductor or solid-state body, e.g. cap-to-substrate
• CPC Class Codes: H01L 2924/206 : Length ranges
• CPC Class Codes: H01Q 21/065 : Patch antenna array
• CPC Class Codes: H01Q 9/0457 : electromagnetically coupled to the feed line

Abstract

Methods and apparatus are presented that reduce the overall system cost for automotive radar sensing applications through reduction of the number of the radar sensors required. In accordance with aspects of the present invention, one way sensor count reduction can be achieved is through the combination of target range, direction, and velocity determination capability with wide angular field of view coverage within a single sensor unit. One embodiment combines a wide field of view antenna means with a wideband/ultra-wideband/precision-ultra-wideband radar transmitter-receiver and an interferometric direction-finding means into a single sensor unit. Other methods and apparatus are presented.

Claims

1. A radar method for motor vehicles for determining characteristics of a target, comprising:

modulating a pulse repetition interval of pulses to generate a transmission signal;

transmitting said transmission signal;

receiving a reflected portion of said transmitted signal from said target by a plurality of antennas to output a plurality of signals representing said reflected portion;

downconverting said plurality of signals;

generating difference signals based on said plurality of signals and said transmission signal;

determining at least one of a target range and a target relative velocity based on at least one of the frequency and phase components of said difference signals; and

determining target direction based on at least one of the amplitude and phase difference between components of at least two of said difference signals.

2. The method of claim 1, wherein determining at least one of said target range and said target relative velocity comprises performing a Fourier transformation on said difference signals and evaluating at least one of the frequency and phase of a peak above a predetermined threshold occurring in said Fourier transformation to determine at least one of said frequency and phase components of said difference signals.

3. The method of claim 2, wherein determining target direction comprises using at least one of the amplitude and phase difference between peaks occurring between said Fourier transformations of at least two difference signals.

4. The method of claim 1, wherein at least two of said antennas have spatially separated locations.

5. The method of claim 1, wherein at least two of said antennas have different directional gain patterns.

6. The method of claim 1, wherein determining target direction comprises using a phase monopulse direction-finding comparison of said difference signals.

7. The method of claim 6, wherein said plurality of antennas comprise a plurality of switched receive beams, each of said switched receive beams having a different directional gain pattern.

8. The method of claim 1, wherein determining target direction comprises using an interferometry direction-finding comparison of said difference signals.

9. The method of claim 8, wherein said plurality of antennas comprise a plurality of switched receive beams, each of said switched receive beams having a different directional gain pattern.

10. The method of claim 1, further comprising determining target direction using a super-resolution algorithm.

11. The method of claim 1, wherein determining target direction comprises using an amplitude monopulse direction-finding comparison of said difference signals.

12. The method of claim 1, wherein modulating a pulse repetition interval of pulses to generate a transmission signal comprises at least one of amplitude modulation, on-off keying, phase modulation, and bi-phase modulation.

13. The method of claim 1, wherein modulating a pulse repetition interval of pulses to generate a transmission signal comprises varying said pulse repetition interval with respect to time during a predetermined time interval.

14. The method of claim 13, wherein varying said pulse repetition interval comprises linear variation.

15. The method of claim 13, wherein varying said pulse repetition interval comprises monotonic variation.

16. The method of claim 1, wherein modulating a pulse repetition interval of pulses comprises stepping of said pulse repetition interval with respect to time during a predetermined time interval.

17. The method of claim 16, wherein said stepping comprises linear stepping.

18. The method of claim 17, further comprising rearranging the order of said stepped pulse repetition interval modulation according to a predetermined order.

19. The method of claim 16, further comprising interleaving a plurality of stepped pulse repetition interval sequences during a predetermined time interval.

20. The method of claim 1, wherein said pulses comprise pulses of a carrier signal.

21. The method of claim 1, wherein transmitting said transmission signal comprises transmitting a single sideband of said transmission signal.

22. The method of claim 1, further comprising interrupting said transmission signal, said interruption occurring at a transmission interruption frequency.

23. The method of claim 1, further comprising interrupting said plurality of signals, said interruption occurring at a reception interruption frequency.

24. The method of claim 1, further comprising interrupting said transmission signal and said plurality of signals, said transmission signal being interrupted when said plurality of signals are not interrupted, and said plurality of signals being interrupted when said transmission signal is not interrupted.

25. The method of claim 24, further comprising performing a second downconversion of said plurality of received signals.

26. The method of claim 1, further comprising performing a second downconversion of said plurality of signals.

27. The method of claim 26, wherein performing a second downconversion of said plurality of signals comprises downconverting with a signal having a frequency equal to a receive interruption frequency.

28. The method of claim 1, wherein said plurality of antennas comprise a plurality of switched receive beams, each of said plurality of switched receive beams having a different directional gain pattern.

29. The method of claim 28, further comprising performing a second downconversion of said plurality of signals.

30. The method of claim 28, further comprising interrupting said plurality of signals with a reception interruption frequency.

31. The method of claim 30, further comprising performing a second downconversion of said plurality of signals.

32. The method of claim 1, wherein a bandwidth occupied by said transmission signal during a coherent measurement time duration is at least wideband.

33. A radar method for motor vehicles for determining characteristics of a target, comprising:

modulating the frequency of a carrier signal to generate a transmission signal using a plurality of discontinuous frequency changes during a coherent measurement time duration;

transmitting said transmission signal;

receiving a reflected portion of said transmitted signal from said target by a plurality of spatially separated antennas to output a plurality of signals representing said reflected portion;

downconverting said plurality of signals;

generating difference signals based on said plurality of signals and said transmission signal;

determining at least one of a target range and a target relative velocity based on at least one of the frequency and phase components of said difference signals; and

determining target direction based on a phase difference between components of at least two of said difference signals.

34. The method of claim 33, wherein determining at least one of said target range and said target relative velocity comprises performing a Fourier transformation on said difference signals and evaluating at least one of the frequency and phase of a peak above a predetermined threshold occurring in said Fourier transformation to determine at least one of said frequency and phase components of said difference signals.

35. The method of claim 34, wherein determining target direction comprises using a phase difference between peaks occurring between said Fourier transformations of at least two difference signals.

36. The method of claim 33, wherein modulating the frequency of a carrier signal to generate a transmission signal using a plurality of discontinuous frequency changes comprises linear frequency stepping with respect to time.

37. The method of claim 36, further comprising interleaving a plurality of stepped frequency sequences.

38. The method of claim 36, further comprising re-arranging the order of said linear frequency stepping modulation according to a predetermined order.

39. The method of claim 33, wherein modulating the frequency of a carrier signal comprises frequency hopping with respect to time.

40. The method of claim 39, further comprising interleaving a plurality of frequency hopped sequences.

41. The method of claim 39, further comprising re-arranging the order of said frequency hopping modulation according to a predetermined order.

42. The method of claim 33, wherein determining target direction comprises using a phase monopulse direction-finding comparison of said difference signals.

43. The method of claim 42, wherein said plurality of spatially separated antennas comprise a plurality of switched receive beams, each of said switched receive beams having a different directional gain pattern.

44. The method of claim 33, wherein determining target direction comprises using an interferometry direction-finding comparison of said difference signals.

45. The method of claim 44, wherein said plurality of spatially separated antennas comprise a plurality of switched receive beams, each of said switched receive beams having a different directional gain pattern.

46. The method of claim 33, wherein determining target direction comprises using a super-resolution algorithm.

47. The method of claim 33, further comprising pulsing said transmission signal through at least one of amplitude modulation, on-off keying, phase modulation, and bi-phase modulation.

48. The method of claim 33, further comprising interrupting said transmission signal, said interruption occurring at an interruption transmission frequency.

49. The method of claim 48, further comprising performing a second downconversion of said difference signals.

50. The method of claim 33, further comprising interrupting said plurality of signals, said interruption occurring at a reception interruption frequency.

51. The method of claim 50, further comprising performing a second downconversion of said difference signals.

52. The method of claim 51, wherein performing a second downconversion comprises downconverting with a downconversion signal having a frequency equal to said reception interruption frequency.

53. The method of claim 33, further comprising interrupting said transmission signal and said plurality of signals, said transmission signal being interrupted during the time when said plurality of signals are not interrupted, and said plurality of signals being interrupted during the time when said transmission signal is not interrupted.

54. The method of claim 33, wherein said plurality of spatially separated antennas comprise a plurality of switched receive beams, each of said switched receive beams having a different directional gain pattern.

55. The method of claim 54, further comprising performing a second downconversion of said difference signals.

56. The method of claim 54, further comprising interrupting said plurality of signals, said interruption occurring at a reception interruption frequency.

57. The method of claim 56, further comprising performing a second downconversion of said difference signals.

58. The method of claim 33, further comprising performing a second downconversion of said difference signals.

59. The method of claim 33, wherein a bandwidth occupied during a coherent measurement time duration of said transmission signal is at least wideband.