Designing an antenna array to meet specified performance criteria

• US 10,312,587 B1
• Filed: 10/16/2017
• Issued: 06/04/2019
• Est. Priority Date: 10/16/2017
• Status: Active Grant

• Current Assignee: L3 Technologies, Inc. (L3Harris Technologies, Inc.)
• Original Assignee: L-3 Communications Corporation (L3Harris Technologies, Inc.)
• Inventors: Zarubica, Radivoje, Kingston, Samuel C., Harker, Neil K., Nelson, N. Thomas
• Primary Examiner(s): Levi, Dameon E
• Assistant Examiner(s): Lotter, David E
• Application Number:
  US15/785,260
• Time in Patent Office: 596 Days
• CPC Class Codes: G01S 3/04 Details
• 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: G01S 5/0218 Multipath in signal reception
• CPC Class Codes: H01Q 21/061 Two dimensional planar arrays
• CPC Class Codes: H01Q 3/267 Phased-array testing or checking devices

Abstract

An antenna array can be quickly and efficiently designed to meet specified performance criteria. A system can be configured to receive various performance criteria as inputs, and from these inputs, identify how elements of an antenna array should be arranged so that the antenna array will meet the performance criteria. An iterative process can be performed to identify at least one arrangement of elements that will best meet the performance criteria while also complying with specified structural constraints.

Claims

1. A method, performed by an antenna array design system, for identifying an arrangement of antenna elements that will meet required performance criteria based on structural constraints, the method comprising:

receiving input that defines required performance criteria for an antenna array, the required performance criteria including an angle of arrival accuracy and a probability of ambiguous arrival;

receiving input that defines structural constraints for the antenna array, the structural constraints including a number of antenna elements, a field of view, and a maximum distance between any two antenna elements in one dimension;

calculating, based on the structural constraints, a number of samples that are required to achieve the angle of arrival accuracy;

calculating, based on the structural constraints and the number of samples, a minimum signal to noise ratio reduction parameter;

identifying, based on the structural constraints, a search space within which antenna elements of the antenna array will be positioned;

selecting a first arrangement of the number of antenna elements within the search space;

calculating, for each of a number of angles within the field of view, a signal to noise ratio reduction parameter for the first arrangement;

determining that a minimum of the noise ratio reduction parameters calculated for the first arrangement exceeds the minimum signal to noise ratio reduction parameter;

calculating, for each of a number of angles within the field of view, an angle of arrival error resulting from coherent multipath for the first arrangement and generating a sum of the angle of arrival errors for the first arrangement;

determining that the sum of the angle of arrival errors for the first arrangement is less than a corresponding sum of angle of arrival errors for one or more other arrangements of antenna elements; and

generating output that identifies that the first arrangement meets the required performance criteria and provides better multipath resistance than the one or more other arrangements.

2. The method of claim 1, wherein the number of samples is calculated based on an angle within the field of view, the maximum distance, the angle of arrival accuracy, and a signal to noise ratio.

3. The method of claim 2, wherein the signal to noise ratio is included in the input that defines the required performance criteria.

4. The method of claim 1, wherein the minimum signal to noise ratio reduction parameter is calculated based on the number of antenna elements, the number of samples, a signal to noise ratio of a signal received at the antenna elements, and a signal to noise ratio at an output of an angle of arrival estimator.

5. The method of claim 1, wherein identifying a search space comprises defining a volume or an area that complies with the maximum distance.

6. The method of claim 5, wherein identifying a search space further comprises defining a volume or an area that will provide the field of view.

7. The method of claim 5, wherein identifying a search space further comprises identifying a number of possible positions with the defined volume or area where an antenna element may be placed, each position being spaced by a defined minimum distance.

8. The method of claim 1, further comprising:

selecting a second arrangement of the number of antenna elements within the search space, the second arrangement being different from the first arrangement;

calculating, for each of the number of angles within the field of view, a signal to noise ratio reduction parameter for the second arrangement;

determining that a minimum of the noise ratio reduction parameters calculated for the second arrangement does not exceed the minimum signal to noise ratio reduction parameter; and

ceasing evaluation of the second arrangement.

9. The method of claim 1, further comprising:

selecting a second arrangement of the number of antenna elements within the search space, the second arrangement being different from the first arrangement;

calculating, for each of the number of angles within the field of view, a signal to noise ratio reduction parameter for the second arrangement;

determining that a minimum of the noise ratio reduction parameters calculated for the second arrangement exceeds the minimum signal to noise ratio reduction parameter;

calculating, for each of a number of angles within the field of view, an angle of arrival error resulting from coherent multipath for the second arrangement and generating a sum of the angle of arrival errors for the second arrangement; and

determining that the sum of the angle of arrival errors for the second arrangement is greater than the sum of the angle of arrival errors for the first arrangement.

10. The method of claim 1, wherein determining that the sum of the angle of arrival errors for the first arrangement is less than a corresponding sum of angle of arrival errors for one or more other arrangements of antenna elements comprises determining that the sum of the angle of arrival errors for the first arrangement is less than a corresponding sum of angle of arrival errors for all other arrangements of antenna elements within the search space.

11. The method of claim 10, wherein the output identifies that the first arrangement provides better multipath resistance than all other arrangements of antenna elements within the search space.

12. The method of claim 1, wherein the search space is an area that aligns with two axes.

13. The method of claim 12, wherein the area only includes positions that lie on one or both of the two axes.

14. An antenna array design system comprising one or more non-transitory computer readable media storing computer-executable instructions which when executed implement a method for identifying an arrangement of antenna elements that will meet required performance criteria based on structural constraints, the method comprising:

receiving input that defines required performance criteria for an antenna array, the required performance criteria including an angle of arrival accuracy and a probability of ambiguous arrival;

receiving input that defines structural constraints for the antenna array, the structural constraints including a number of antenna elements, a field of view, and a maximum distance between any two antenna elements in one dimension;

calculating, based on the structural constraints, a number of samples that are required to achieve the angle of arrival accuracy;

calculating, based on the structural constraints and the number of samples, a minimum signal to noise ratio reduction parameter;

identifying, based on the structural constraints, a search space within which antenna elements of the antenna array will be positioned; and

iteratively evaluating a plurality of possible arrangements of the antenna elements within the search space including, for each possible arrangement;

calculating, for each of a number of angles within the field of view, a signal to noise ratio reduction parameter for the arrangement;

determining whether a minimum of the noise ratio reduction parameters calculated for the arrangement exceeds the minimum signal to noise ratio reduction parameter;

when the minimum of the noise ratio reduction parameters calculated for the arrangement exceeds the minimum signal to noise ratio reduction parameter, calculating, for each of a number of angles within the field of view, an angle of arrival error resulting from coherent multipath for the arrangement and generating a sum of the angle of arrival errors for the arrangement; and

determining whether the sum of the angle of arrival errors for the arrangement is less than a corresponding sum of angle of arrival errors for previously evaluated arrangements, and if so, saving the arrangement as a best arrangement.

15. The antenna array design system of claim 14, wherein the method further comprises:

after iteratively evaluating the plurality of possible arrangements, outputting the best arrangement.

16. The antenna array design system of claim 14, wherein when the minimum of the noise ratio reduction parameters calculated for the arrangement does not exceed the minimum signal to noise ratio reduction parameter, evaluation of the arrangement is terminated.

17. The antenna array design system of claim 14, wherein the arrangement is saved as the best arrangement when the sum of the angle of arrival errors for the arrangement is less than a corresponding sum of angle of arrival errors for all previously evaluated arrangements.

18. The antenna array design system of claim 14, wherein the number of samples is calculated based on an angle within the field of view, the maximum distance, the angle of arrival accuracy, and a signal to noise ratio.

19. A method, performed by an antenna array design system, for identifying an arrangement of antenna elements that will meet required performance criteria based on structural constraints, the method comprising:

receiving input that defines required performance criteria for an antenna array, the required performance criteria including an angle of arrival accuracy and a probability of ambiguous arrival;

receiving input that defines structural constraints for the antenna array;

calculating, based on the structural constraints, a number of samples that are required to achieve the angle of arrival accuracy;

calculating, based on the structural constraints and the number of samples, a minimum signal to noise ratio reduction parameter;

identifying, based on the structural constraints, a search space within which antenna elements of the antenna array will be positioned;

iteratively evaluating a plurality of possible arrangements of a number of antenna elements within the search space including, for each possible arrangement;

calculating, for each of a number of angles, a signal to noise ratio reduction parameter for the arrangement;

determining whether a minimum of the noise ratio reduction parameters calculated for the arrangement exceeds the minimum signal to noise ratio reduction parameter;

when the minimum of the noise ratio reduction parameters calculated for the arrangement exceeds the minimum signal to noise ratio reduction parameter, calculating, for each of a number of angles, an angle of arrival error resulting from coherent multipath for the arrangement and generating a sum of the angle of arrival errors for the arrangement; and

determining whether the sum of the angle of arrival errors for the arrangement is less than a corresponding sum of angle of arrival errors for previously evaluated arrangements, and if so, saving the arrangement as a best arrangement.

20. The method of claim 19, wherein the structural constraints include one or more of:

a number of antenna elements;

a field of view;

or

a maximum distance between any two antenna elements in one dimension.