Steerable beamforming system

• US 6,552,964 B2
• Filed: 04/06/2001
• Issued: 04/22/2003
• Est. Priority Date: 02/03/1997
• Status: Expired due to Term

• Current Assignee: Teratech Corporation
• Original Assignee: Teratech Corporation
• Inventors: Chiang, Alice M., Broadstone, Steven R.
• Primary Examiner(s): Pihulic, Daniel T.
• Application Number:
  US09/828,266
• Publication Number:
  US 20020064093A1
• Time in Patent Office: 746 Days
• Field of Search: 367/138, 367/7, 367/11, 367/103, 367/119, 342/154, 342/179, 342/180, 600/447
• US Class Current: 367/138
• 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

The need for multiple, cost-effective deployment of an underwater camera has resulted in the development of a low-power high-resolution imaging system using a sparse array. The system can be used for undersea acoustic mine-field reconnaissance and mine-hunting systems for example, this imaging sonar is portable enough for use in a diver'"'"'s hands or in a remote imaging sonar on an unmanned undersea vehicle in shallow waters. The present system can simultaneously focus many signals using multiple CCD/CMOS, programmable time-delay beamforming circuits connected to a sparsely-populated 2D acoustic array, is being developed. Using this approach, a real-time image can be formed to search for mine-like objects. To make a sparse array, the combination of low insertion loss and wide bandwidth performance is important for realizing acceptable imaging performance with low illumination levels.

Claims

1. A two-dimensional beamforming system comprising:

a two-dimensional transducer array, the transducer array comprising a water borne array for a sonar system, the array having a plurality of subarrays, each subarray being connected to a subarray processor such that each subarray is simultaneously separately steerable by the processor and each subarray transducer element having a delay line having at least one hundred stages; and

a charge domain beamforming processor connected to the array that forms an electronic representation of a region of interest, the processor comprising a charge coupled device that steers array elements in different directions.

2. The system of claim 1 wherein the processor further comprises a plurality of finite impulse response filters.

3. The system of claim 1 further comprising a zoom control to control the depth of view of the array.

4. The system of claim 1 wherein the charge domain beamformer processor is coupled to a memory circuit.

5. The system of claim 1 wherein the processor is connected to a personal computer having a second processor and a user interface.

6. The system of claim 1 wherein the electronic representation of the region of interest is a multi-dimensional image.

7. A two-dimensional beamforming system comprising:

a two-dimensional transducer array, the transducer array comprises a plurality of subarrays, and comprises a water borne array for a sonar system; and

a charge domain beamforming processor connected to the array that forms an electronic representation of a region of interest, the processor comprising a charge coupled device, a plurality of delay lines and a plurality of finite impulse response filters, the processor steering array elements in different directions, and each subarray being simultaneously separately steerable by the processor.

8. The system of claim 7 further comprising a zoom control to control the depth of view of the array.

9. The system of claim 7 wherein the charge domain beamformer processor is coupled to a memory circuit.

10. The system of claim 7 wherein the processor is connected to a personal computer having a second processor and a user interface.

11. The system of claim 7 wherein the electronic representation of the region of interest is a multi-dimensional image.

12. A two-dimensional beamforming system comprising:

a two-dimensional transducer array, the transducer array comprises a plurality of subarrays, and comprises a water borne array for a sonar system;

a charge domain beamforming processor connected to the array that forms an electronic representation of a region of interest, the processor comprising a charge coupled device, a plurality of delay lines and a plurality of finite impulse response filters, the processor steering array elements in different directions, and each subarray being simultaneously separately steerable by the processor; and

a zoom control to control the depth of view of the array.

13. The system of claim 12 wherein the charge domain beamformer processor is coupled to a memory circuit.

14. The system of claim 12 wherein the processor is connected to a personal computer having a second processor and a user interface.

15. The system of claim 12 wherein the electronic representation of the region of interest is a multi-dimensional image.