System and method of acoustic doppler beamforming

Abstract

A system and method for forming acoustic beams is disclosed. One embodiment is an acoustic system configured to generate a plurality of beams non-orthogonal to a transducer array simultaneously with a vertical acoustic beam orthogonal to the array. The acoustic system includes a plurality of transducer elements arranged to form a two-dimensional array and electrically connected into rows in a first dimension and columns in a second dimension.

What is claimed is: 
     
       1. An acoustic system, comprising:
 a plurality of transducer elements arranged to form a two-dimensional array and electrically connected into rows in a first dimension and columns in a second dimension; 
 at least two first beamforming circuits configured to generate a plurality of beams in at least two planes, each of the beams defining a non-orthogonal angle with the transducer array; and 
 a second beamforming circuit electrically connected to each of the first beamforming circuits and configured to generate a beam orthogonal to the transducer array, 
 wherein each of the first beamforming circuits is electrically connected to each of the transducer elements so that each of the transducer elements contributes to each of the beams in the at least two planes. 
 
     
     
       2. The system of  claim 1 , wherein the plurality of beams comprises a Janus configuration that is formed simultaneously with the vertical beam. 
     
     
       3. The system of  claim 1 , wherein the second beamforming circuit comprises a common mode electrical connection to each of the first beamforming circuits. 
     
     
       4. The system of  claim 1 , wherein each of the first beamforming circuits are connected to a virtual ground node for all rows and columns. 
     
     
       5. The system of  claim 4 , wherein each of the first beamforming circuits is connected to the transducer array via a respective transformer. 
     
     
       6. The system of  claim 5 , wherein the second beamforming circuit comprises a second transformer connected to the center tap of each of the respective transformers of each of the first beamforming circuits. 
     
     
       7. The system of  claim 6 , wherein the second transformer provides a common mode electrical connection to the respective transformers of each of the first beamforming circuits. 
     
     
       8. The system of  claim 1 , wherein the second beamforming circuit is connected to less than all of the transducer elements. 
     
     
       9. The system of  claim 8 , wherein the less than all of the transducer elements are adjacent to each other and positioned substantially in the center of the array of transducer elements. 
     
     
       10. The system of  claim 1 , wherein the second beamforming circuit is connected to each of the transducer elements. 
     
     
       11. The system of  claim 1 , wherein the first beamforming circuits are configured to phase shift signals in adjacent rows and columns of the transducer elements. 
     
     
       12. A system for generating a plurality of acoustic beams, the system comprising:
 means for generating a plurality of acoustic signals, the means comprising a plurality of means for converting between an electrical signal and a respective one of the acoustic signals, wherein the converting means are arranged to form a two dimensional array and electrically connected into rows in a first dimension and columns in a second dimension; 
 means for simultaneously forming a plurality of first beams in at least two planes based on the acoustic signals, each of the first beams defining a non-orthogonal angle with the transducer array and wherein each of the first beams is based on each of the respective plurality of signals of each of the converting means; and 
 means for forming a second beam orthogonal to the array based on the acoustic signals, wherein the first and second beams are formed simultaneously. 
 
     
     
       13. The system of  claim 12 , wherein the plurality of beams comprises a Janus configuration that is formed simultaneously with the vertical beam. 
     
     
       14. The system of  claim 12 , wherein the means for forming the second beams comprises a common mode electrical connection to means for forming the first beams. 
     
     
       15. The system of  claim 12 , wherein each of the means for forming the first beams are connected to a virtual ground node for all rows and columns. 
     
     
       16. The system of  claim 15 , wherein the means for forming the first beams comprises at least two beamforming circuits and where each of the first beamforming circuits is connected to the transducer array via a respective transformer. 
     
     
       17. The system of  claim 16  wherein the means for forming the second beam comprises a second beamforming circuit, and wherein the second beamforming circuit comprises a second transformer connected to the center tap of each of the respective transformers of each of the first beamforming circuits. 
     
     
       18. The system of  claim 17 , wherein the second transformer provides a common mode electrical connection to the respective transformers of each of the first beamforming circuits. 
     
     
       19. The system of  claim 12 , wherein means for forming the second beam is connected to less than all of the converting means. 
     
     
       20. The system of  claim 19 , wherein the less than all of the transducer elements are adjacent to each other and positioned substantially in the center of the array of transducer elements. 
     
     
       21. The system of  claim 12 , wherein means for forming the second beam is connected to each of the converting means. 
     
     
       22. The system of  claim 12 , wherein means for forming the first beams are configured to phase shift signals in adjacent rows and columns of the converting means. 
     
     
       23. A method of generating a plurality of acoustic beams, the method comprising:
 generating a plurality of acoustic signals in each of a plurality of transducer elements arranged to form a two dimensional array and electrically connected into rows in a first dimension and columns in a second dimension; 
 simultaneously forming a plurality of first beams in at least two planes based on the acoustic signals using at least two first beamforming circuits, each of the first beams defining a non-orthogonal angle with the transducer array and wherein each of the first beams is based on each of the respective plurality of signals of each of the transducer elements; and 
 forming a second beam orthogonal to the transducer array based on the acoustic signals using a second beamforming circuit, wherein the first and second beams are formed simultaneously. 
 
     
     
       24. The method of  claim 23 , wherein the plurality of beams comprises a Janus configuration that is formed simultaneously with the vertical beam. 
     
     
       25. The method of  claim 23 , wherein the second beam is formed based on the signals of less than all of the transducer elements. 
     
     
       26. The method of  claim 25 , wherein the less than all of the transducer elements are adjacent to each other and positioned substantially in the center of the array of transducer elements. 
     
     
       27. The method of  claim 23 , further comprising phase shifting the acoustic signals adjacent one of the rows and columns of transducer elements. 
     
     
       28. The system of  claim 1 , further comprising controlling the aperture of the beam orthogonal to the transducer array by selecting at least one transducer element, the selected at least one transducer element comprising less than all of the transducer elements. 
     
     
       29. The method of  claim 23 , further comprising controlling the aperture of the beam orthogonal to the transducer array by selecting at least one transducer element, the selected at least one transducer element comprising less than all of the transducer elements. 
     
     
       30. An acoustic system, comprising:
 a plurality of transducer elements arranged to form a two-dimensional array and electrically connected into rows in a first dimension and columns in a second dimension;   a first beamforming circuit configured to generate a plurality of beams in at least two planes, each of the beams defining a non-orthogonal angle with the transducer array; and   a second beamforming circuit electrically connected to the first beamforming circuit and configured to generate a beam orthogonal to the transducer array, wherein the first beamforming circuit is electrically connected to each of the transducer elements so that each of the transducer elements contributes to each of the beams in the at least two planes.    
     
     
       31. The system of claim 30, wherein the plurality of beams comprises a Janus configuration that is formed simultaneously with the vertical beam. 
     
     
       32. The system of claim 30, wherein the second beamforming circuit comprises a common mode electrical connection to each of the first beamforming circuits.  
     
     
       33. The system of claim 30, wherein the first beamforming circuit is connected to a virtual ground node for all rows and columns.  
     
     
       34. The system of claim 33, wherein the first beamforming circuit is connected to the transducer array via a respective transformer.  
     
     
       35. The system of claim 34, wherein the second beamforming circuit comprises a second transformer connected to the center tap of each of the respective transformers of the first beamforming circuit.  
     
     
       36. The system of claim 35, wherein the second transformer provides a common mode electrical connection to the respective transformers of the first beamforming circuit.  
     
     
       37. The system of claim 30, wherein the second beamforming circuit is connected to less than all of the transducer elements.  
     
     
       38. The system of claim 37, wherein the less than all of the transducer elements are adjacent to each other and positioned substantially in the center of the array of transducer elements.  
     
     
       39. The system of claim 30, wherein the second beamforming circuit is connected to each of the transducer elements.  
     
     
       40. The system of claim 30, wherein the first beamforming circuit is configured to phase shift signals in adjacent rows and columns of the transducer elements.  
     
     
       41. A method of generating a plurality of acoustic beams, the method comprising:
 generating a plurality of acoustic signals in each of a plurality of transducer elements arranged to form a two dimensional array and electrically connected into rows in a first dimension and columns in a second dimension;   simultaneously forming a plurality of first beams in at least two planes based on the acoustic signals using a first beamforming circuit, each of the first beams defining a non-orthogonal angle with the transducer array and wherein each of the first beams is based on each of the respective plurality of signals of each of the transducer elements; and   forming a second beam orthogonal to the transducer array based on the acoustic signals using a second beamforming circuit, wherein the first and second beams are formed simultaneously.    
     
     
       42. The method of claim 41, wherein the plurality of beams comprises a Janus configuration that is formed simultaneously with the vertical beam.  
     
     
       43. The method of claim 41, wherein the second beam is formed based on the signals of less than all of the transducer elements.  
     
     
       44. The method of claim 43, wherein the less than all of the transducer elements are adjacent to each other and positioned substantially in the center of the array of transducer elements.  
     
     
       45. The method of claim 41, further comprising phase shifting the acoustic signals adjacent one of the rows and columns of transducer elements.  
     
     
       46. The system of claim 30, further comprising controlling the aperture of the beam orthogonal to the transducer array by selecting at least one transducer element, the selected at least one transducer element comprising less than all of the transducer elements.  
     
     
       47. The method of claim 41, further comprising controlling the aperture of the beam orthogonal to the transducer array by selecting at least one transducer element, the selected at least one transducer element comprising less than all of the transducer elements.