Two dimensional quantization method for array beam scanning

• US 7,327,313 B2
• Filed: 11/19/2004
• Issued: 02/05/2008
• Est. Priority Date: 11/19/2004
• Status: Expired due to Fees

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Hemmi, Christian O., Ball, Brian L., Mccullough, Marc H.
• Primary Examiner(s): Tarcza; Thomas H.
• Assistant Examiner(s): Nguyen; Nga X
• Application Number:
  US10/993,830
• Publication Number:
  US 20060119510A1
• Time in Patent Office: 1,173 Days
• Field of Search: 342368-377, 342/81
• US Class Current: 342/368
• CPC Class Codes: H01Q 3/38 the phase-shifters being digital
• CPC Class Codes: H01Q 3/385 Scan control logics

Abstract

According to one embodiment of the invention, a method of increasing a phase resolution of an array antenna, comprises providing an array antenna having a plurality of rows of antenna elements, each antenna element having a first phase resolution; for at least one row of the array antenna, positioning each of the antenna elements to one of first and second phases, the first and second phases separated by at least the first phase resolution; for the at least one row of the array antenna, a number of antenna elements positioned to the first phase is the product of a number of antenna elements in the at least one row of the array antenna and a desired row phase angle divided by the first phase resolution; and for the at least one row of the array antenna, a number of antenna elements positioned to the second phase is the number of elements in the at least one row of the array antenna minus the number of antenna elements in the at least one row positioned to the first phase.

Claims

1. A method of increasing a phase resolution of an array antenna, the method comprising:

providing an array antenna having a plurality of rows of antenna elements, each antenna element having a first phase resolution and emitting a signal; and

for at least one row of the array antenna, manipulating the signal of each of the antenna elements to one of first and second phases, the first and second phases separated by at least the first phase resolution, wherein;

for the at least one row of the array antenna, a number of antenna elements with signals manipulated to the first phase is the product of a number of antenna elements in the at least one row of the array antenna and a desired row phase angle divided by the first phase resolution, and

for the at least one row of the array antenna, a number of antenna elements with signals manipulated to the second phase is the number of elements in the at least one row of the array antenna minus the number of antenna elements with signals manipulated to the first phase in the at least one row.

2. The method of claim 1, wherein the number of antenna elements manipulated to the first phase in the at least one row are approximately uniformly distributed across the at least one row and approximately distributed symmetrically about a center of the at least one row.

3. The method of claim 1, further comprising:

selecting a phase gradient across the rows, the phase gradient across the rows defining the desired row phase angle for each row; and

for each row, manipulating the signal of each of the antenna elements to one of the first and second phases, wherein the number of antenna elements with signals manipulated to the first and second phases is selected such that the average of phases for each row approximates the desired row phase angle for each row.

4. The method of claim 1, wherein the array antenna includes at least one column, further comprising:

manipulating the signal of each of the antenna elements of the at least one column to one of first and second phases, the first and second phases separated by at least the first phase resolution, wherein;

for the at least one column of the array antenna, a number of antenna elements with signals manipulated to the first phase is the product of a number of antenna elements in the at least one column of the array antenna and a desired column phase angle divided by the first phase resolution; and

for the at least one column of the array antenna, a number of antenna elements with signals manipulated to the second phase is the number of elements in the at least one column of the array antenna minus the number of antenna elements with signals manipulated to the first phase in the at least one column.

5. The method of claim 4, wherein the array antenna includes a plurality of columns, further comprising:

selecting a phase gradient across the columns, the phase gradient across the columns defining the desired column phase angle for each column; and

for each column, manipulating the signal of each of the antenna elements to one of the first and second phases, wherein the number of elements manipulated to the first and second phases is selected such that the average of phases for each column approximates the desired column phase angle for each column.

6. The method of claim 1, wherein the first phase resolution is at least 45 degrees.

7. The method of claim 1, wherein an increased phase resolution for each row is the first phase resolution divided by the number of elements in each row.

8. The method of claim 7, wherein the increased phase resolution for each row is less than 3.0 degrees.

9. The method of claim 7, wherein the increased phase resolution for each row is less than 1.5 degrees.

10. An antenna array, comprising:

a plurality of rows of antenna elements, wherein;

each antenna element has a first phase resolution and emits a signal,

at least one row of the array antenna has each of signals in the at least one row manipulated to one of first and second phases,

the first and second phases are separated by at least the first phase resolution,

for the at least one row of the array antenna, a number of antenna elements with signals manipulated to the first phase is the product of a number of antenna elements in the at least one row of the array antenna and a desired row phase angle divided by the first phase resolution, and

for the at least one row of the array antenna, a number of antenna elements with signals manipulated to the second phase is the number of elements in the at least one row of the array antenna minus the number of antenna elements with signals manipulated to the first phase in the at least one row.

11. The antenna array of claim 10, further comprising:

a plurality of digital phase shifters, operable to shift the phases of the signals of each element, wherein;

each of the plurality of digital phase shifters receives a number of bits that define a phase setting of a signal for the elements; and

an effective phase resolution for each element of the antenna array is less than 360/2^N, where N is the number of bits that define the phase setting.

12. The antenna array of claim 10, further comprising:

a phase gradient across the rows, wherein;

the phase gradient across the rows define a desired row phase angle for each row;

each row has the signal of each of the antenna elements manipulated to one of the first and second phases; and

the number of antenna elements with signals manipulated to the first and second phases is selected such that the average of phases for each row approximates the desired row phase angle for each row.

13. The antenna array of claim 10, further comprising:

at least one column of antenna elements, wherein

each of the signals of the antenna elements in the at least one column is manipulated to one of first and second phases,

for the at least one column of the array antenna, a number of antenna elements with signals manipulated to the first phase is the product of a number of antenna elements in the at least one column of the array antenna and a desired column phase angle divided by the first phase resolution, and

for the at least one column of the array antenna, a number of antenna elements with signals manipulated to the second phase is the number of elements in the at least one column of the array antenna minus the number of antenna elements with signals manipulated to the first phase in the at least one column.

14. The antenna array of claim 12, further comprising:

a plurality of columns of antenna elements; and

a phase gradient across the columns, wherein;

the phase gradient across the columns defines a desired column phase angle for each column;

each column has the signal of each of the antenna elements positioned to one of the first and second phases; and

the number of elements manipulated to the first and second phases is selected such that the average of phases for each column approximates the desired column phase angle for each column.

15. The antenna array of claim 10, wherein the first phase resolution is at least 45 degrees.

16. The antenna array of claim 10, wherein an increased phase resolution for each row is the first phase resolution divided by the number of elements in each row.

17. The antenna array of claim 16, wherein the increased phase resolution for each row is less than 3.0 degrees.

18. The antenna array of claim 16, wherein the increased phase resolution for each row is less than 1.5 degrees.