Multi-dimensional beamforming device

• US 20020012289A1
• Filed: 08/02/2001
• Published: 01/31/2002
• Est. Priority Date: 02/03/1997
• Status: Active Grant

• Current Assignee: Teratech Corporation
• Original Assignee: Teratech Corporation
• Inventors: Chiang, Alice M., Gilbert, Jeffrey M., Broadstone, Steven R.
• Granted Patent: US 6,671,227 B2
• Time in Patent Office: Days
• US Class Current: 367/135
• CPC Class Codes: G01S 15/8927 using simultaneously or sequentially two or more subarrays or subapertures
• CPC Class Codes: G01S 7/52085 Details related to the ultrasound signal acquisition, e.g. scan sequences control of medical diagnostic ultrasound devices A61B8/54
• CPC Class Codes: G01S 7/52095 using multiline receive beamforming
• CPC Class Codes: G10K 11/346 using phase variation
• 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 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence
• CPC Class Codes: H01Q 3/2682 Time delay steered arrays

Abstract

A multidimensional beamforming device that performs consecutive one-dimensional operations. For example, beamsteering for a two-dimensional array can be include a projection of a beam onto each of the respective axes of the array. In such a device, a first beamforming processing element is used to form multiple beams for each array output along a given row. In a preferred embodiment, sequential output vectors from the first processing element are then applied to a transposing or corner turning memory and the data are reformatted such that all elements on a given column of the array are applied to a second beam forming processing element.

Claims

1. A sonar beamforming system, comprising in combination:

a plurality of sensors disposed in a sensor array that provide array signals; and

a beamforming device, coupled to the sensor array, the beamforming device including a plurality of charge domain delay lines that generate delayed output signals from the array signals to form a representation of a region of interest from the delayed output signals.

2. The system of claim 1, further comprising a transposer device, coupled between the beamforming device and a second beamforming device, for transposing the delayed output signals generated by the first beamforming device such that the second beamforming device generates a representation of the region of interest based on the transposed delayed output signals.

3. The system of claim 1, wherein each of the plurality of sensors is a hydrophone.

4. The system of claim 2, wherein at least one of the first and second beamforming device further comprises a plurality of tapped delay lines.

5. The system of claim 4, wherein each tapped delay line comprises a charge coupled device.

6. The system of claim 1, wherein the beamforming device comprises an integrated circuit.

7. The system of claim 2, wherein the second beamforming device comprises an integrated circuit.

8. The system of claim 1, wherein the beamforming device comprises a sampling circuit coupled to a programmable delay circuit, a weighting circuit and a summing circuit.

9. The system of claim 8, further comprising a filtering circuit coupled between the summing circuit and a display device.

10. The system of claim 1, wherein each sensor in the plurality of sensors is spaced apart along a linear array.

11. The system of claim 1, wherein the difference between the sensor array spacing and a distance to a source is at least two orders of magnitude.

12. The system of claim 1, wherein outputs of the plurality of sensors are multiplied by weighting factors and summed.

13. The system of claim 1, wherein the sensor array includes subarrays of sensor elements.

14. The system of claim 1, wherein the first beamforming device has a plurality of tap positions, each tap position being programmable, and includes groups of first delay lines corresponding to the subarrays of the sensor array, each first delay line of a group being coupled to a sensor element of that group'"'"'s corresponding subarray.

15. An electronically steerable sonar system comprising in combination:

a sensor array including a first plurality of sensor elements;

a programmable tapped delay line device that receives signals from the sensor array and that generates delayed output signals to form a representation of a region of interest;

a tap selection circuit connected to the delay line device to control tap selection;

and

a controller connected to the tap selection circuit that controls programmed tap selection for the delay line device.

16. The system of claim 15, wherein the sensor array comprises a plurality of independently controllable subarrays.

17. The system of claim 15, wherein each delay line device comprises a charge coupled device.

18. The system of claim 15, further comprising a down conversion circuit.

19. The system of claim 15, further comprising a scan controller to scan the array across an image plane.

20. The system of claim 16, further comprising a plurality of delay lines for each subarray, and output of each delay line being summed an input into the second programmable delay line.

21. The system of claim 15, wherein the delay line device comprises a plurality of beamforming delay lines coupled to a summing circuit, the summing circuit being connected to an input for second tapped delay line device.

22. The system of claim 15, further comprising a sampling circuit connected to the sensor array and the delay line device.

23. The system of claim 15, further comprising a down-conversing circuit and a low pass filter.

24. A method for sonar beamforming comprising the steps of:

obtaining array signals from a plurality of sensors disposed in a sensor array; and

programming a beamforming device which includes a plurality of charge domain delay lines to generate delayed output signals from the array signals to form a representation of a region of interest from the delayed output signals.

25. The method of claim 24, further comprising a step of:

transposing the delayed output signals generated by the beamforming device to form transposed delayed output signals such that a second beamforming device generates a representation of the region of interest based on the transposed delayed output signals.

26. The method of claim 24, wherein the step of obtaining array signals comprises obtaining array signals from a plurality of hydrophones.

27. The method of claim 24, further comprising the step of:

programming a second beamforming device which includes a plurality of charge domain delay lines that receives the delayed output signals to generate a multi-dimensional representation of a region of interest from the delayed output signals.

28. The method of claim 24, wherein the step of programming the beamforming device includes forming beams along a first set of angles formed with respect to a first plane, and programming a second beamforming device for forming beams along a second set of angles formed with respect to a second plane that is non-planar with the first plane.

29. The method of claim 24, wherein the step of programming the beamforming device includes forming a first representation having a first resolution and forming a second representation generated by a second beamforming device having a second resolution that is lower than the first resolution.

30. The system of claim 24, wherein the step of obtaining array signals further comprises multiplying and summing outputs of the plurality of sensors by weighting factors.

31. A method for providing an electronically steerable sonar system comprising the steps of:

obtaining array signals from a sensor array including a first plurality of sensor elements;

programming a programmable tapped delay line device that receives signals from the sensor array and that generates delayed output signals to form a representation of a region of interest; and

controlling a programmed tap selection to the delay line device using a tap selection circuit.

32. The method of claim 31, further comprising a step of:

transposing the delayed output signals generated by the programmable tapped delay line device to form transposed delayed output signals such that a second programmed tapped delay line device generates a representation of the region of interest based on the transposed delayed output signals.

33. The method of claim 31, wherein the step of obtaining array signals comprises obtaining array signals from a plurality of hydrophones.

34. The method of claim 31, further comprising the step of:

programming a second programmable tapped delay line device which includes a plurality of charge domain delay lines that receives the delayed output signals to generate a multi-dimensional representation of a region of interest from the delayed output signals.

35. The method of claim 31, wherein the step of programming the programmable tapped delay line device includes forming beams along a first set of angles formed with respect to a first plane, and programming a second programmable tapped delay line device for forming beams along a second set of angles formed with respect to a second plane that is non-planar with the first plane.

36. The method of claim 31, wherein the step of programming the programmable tapped delay line device includes forming a first representation having a first resolution and forming a second representation generated by a second programmable tapped delay line device having a second resolution that is lower than the first resolution.