Phase arrays exploiting geometry phase and methods of creating such arrays

• US 7,714,782 B2
• Filed: 04/26/2007
• Issued: 05/11/2010
• Est. Priority Date: 01/13/2004
• Status: Expired due to Fees

• Current Assignee: Dennis Willard Davis, Phillip David Neumiller, Román, Jaime R.
• Original Assignee: Dennis Willard Davis, Phillip David Neumiller, Román, Jaime R.
• Inventors: Davis, Dennis Willard, Neumiller, Phillip David, Román, Jaime R.
• Primary Examiner(s): Phan; Dao L
• Application Number:
  US11/796,463
• Publication Number:
  US 20070285315A1
• Time in Patent Office: 1,111 Days
• Field of Search: 342/99, 342/158, 342/360, 342/368, 342/377, 342/408, 342/442, 342/443, 342/450
• US Class Current: 342/377
• CPC Class Codes: G01S 3/54 the apparent movement of the antenna being produced by coupling the receiver cyclically and sequentially to each of several fixed spaced antennas
• CPC Class Codes: G01S 3/74 Multi-channel systems specially adapted for direction-finding, i.e. having a single antenna system capable of giving simultaneous indications of the directions of different signals systems in which the directions of different signals are determined sequentially and displayed simultaneously G01S3/04, G01S3/14
• CPC Class Codes: H01Q 21/22 Antenna units of the array energised non-uniformly in amplitude or phase, e.g. tapered array or binomial array
• CPC Class Codes: H01Q 3/2629 Combination of a main antenna unit with an auxiliary antenna unit

Abstract

In the context of array sensors such as radar, sonar, and communications receiver arrays, the present invention exploits the geometry phase components of radiated wavefronts associated with the signals of interest in order to reduce the bandwidth requirements for DOA and beamforming processing. Additionally, geometry phase is exploited in order to effectively increase the resolution of an array without changing the size of its physical footprint or the number of array elements. Other embodiments of the invention include the use of virtual array elements for increase in effective array size.

Claims

1. A method of creating a geometry phase processing-based phased array of receiving elements comprising the steps of:

a) extracting the geometry phase associated with each of a plurality of remote emitting sources received by each said element of said array; and

b) scaling said geometry phase to improve properties of the array taken from the group comprising (i) increase in the angular resolution of said array and (ii) reduction in the physical size of said array.

2. The method recited in claim 1 wherein said scaling of geometry phase is used to increase the resolution of said array without altering the separation between said array elements.

3. The method recited in claim 1 wherein said scaling of geometry phase is used to maintain the resolution of said array without altering the separation between said array elements, but with reducing the number of said receiving elements.

4. The method recited in claim 1 wherein said scaling of geometry phase is used to reduce the separation between said array elements without reducing the resolution of said array.

5. The method recited in claim 1 wherein processing of said geometry phase permits narrowband beamforming and direction of arrival processing for wideband received signals without substantial loss of array performance.

6. The method recited in claim 1 wherein step b includes creation of virtual array elements that increase the effective array size.

7. The method recited in claim 1 wherein said step b) includes the steps:

i) forming multiple receive beams; and

ii) scaling the geometry phase for each said beam independently.

8. A method of creating a geometry phase processing-based phased array of receiving elements comprising the steps of:

a) estimating the geometry phase of each said remote emitting source using direction of arrival estimation methods; and

b) scaling said geometry phase to improve properties of the array taken from the group comprising (i) increase in the angular resolution of said array and (ii) reduction in the physical size of said array.

9. The method recited in claim 8 wherein steps a and b are executed iteratively to achieve array performance.

10. A method of creating a geometry phase processing-based phased array of receiving elements comprising the steps of:

a) providing an array with an initial number of active receiving elements;

b) extracting the geometry phase associated with each of a plurality of remote emitting sources received by each said element of said array;

c) scaling said geometry phase to reduce said initial number of said active receiving elements while substantially maintaining the resolution of said array.

11. A phased array sensor comprising:

a) a collection of array receiving elements, receiving energy from at least one remote source;

b) means for extracting the geometry phase associated with each said element attributable to each said remote source; and

c) means for scaling said geometry phase to proportionally increase the resolution of said array.