Low loss, variable phase reflect array

• US 8,217,847 B2
• Filed: 09/26/2007
• Issued: 07/10/2012
• Est. Priority Date: 09/26/2007
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Sotelo, Michael John, Brown, Kenneth William
• Primary Examiner(s): DUONG, DIEU HIEN
• Application Number:
  US11/861,621
• Publication Number:
  US 20090079645A1
• Time in Patent Office: 1,749 Days
• Field of Search: 343/755, 343/756, 343/909, 343/912, 343/700.MS
• US Class Current: 343/755
• CPC Class Codes: H01Q 15/0013 said selective devices working as frequency-selective reflecting surfaces, e.g. FSS, dichroic plates, surfaces being partly transmissive and reflective
• CPC Class Codes: H01Q 15/0046 Theoretical analysis and design methods of such selective devices
• CPC Class Codes: H01Q 15/14 Reflecting surfaces; Equivalent structures electromagnetic shields H01Q1/526
• CPC Class Codes: H01Q 3/46 Active lenses or reflecting arrays

Abstract

There is disclosed reflect array including a dielectric substrate having a first surface and a second surface. The first surface may support a first array of phasing elements and a second array of phasing element, where the elements of the first array have a first shape and the elements of the second array may have a second shape different from the first shape. The second surface may support a conductive layer.

Claims

1. A reflect array, comprising:

a dielectric substrate having a first surface and a second surface;

a continuous conductive layer on the second surface; and

a first array of phasing elements and a second array of phasing elements interleaved in a single layer on the first surface, the elements of the first array having a first shape and the elements of the second array having a second shape different from the first shape;

wherein the first array and the second array are collectively configured to reflect an incident microwave beam in a predetermined frequency band to provide a reflected beam, the reflected beam having a phase shift relative to the incident beam that is determined, at least in part, by dimensions of the elements of both the first and second arrays of phasing elements; and

wherein a spacing between adjacent elements of the second array is substantially equal to a spacing between adjacent elements in the first array.

2. The reflect array of claim 1, wherein the elements of the first array are “

X”

shapes and the elements of the second array are square patches.

3. The reflect array of claim 1, wherein the phase shift at any point within an extent of the reflect array can be set to any value within a continuous range spanning more than 315 degrees by setting dimensions of the phasing elements in the first and second arrays.

4. The reflect array of claim 3, wherein:

the dielectric substrate has a first curvature, and

the phase shift is varied across the reflect array to cause the reflect array to emulate a reflector having a second curvature different from the first curvature.

5. The reflect array of claim 4, wherein:

the dielectric substrate is planar, and

the reflect array emulates a non-planar reflector.

6. The reflect array of claim 5, wherein the reflect array emulates a curved reflector selected from the group consisting of a parabolic reflector, a spherical reflector, a cylindrical reflector, a torroidal reflector, a conic reflector, and a generalized aspheric reflector.

7. The reflect array of claim 3, wherein the phase shift at any point within the extent of the reflect array can be set to any value within a continuous range spanning more than 355 degrees by setting the dimensions of the phasing elements in the first and second arrays.

8. The reflect array of claim 1, wherein:

the elements of the first array are disposed on a rectangular grid, and

the elements of the second array are disposed in interstitial spaces between the elements of the first array.

9. The reflect array of claim 8, wherein:

a spacing between adjacent rows and columns of the rectangular grid is less than a wavelength of microwave radiation in the incident microwave beam.

10. The reflect array of claim 9, wherein:

the spacing between adjacent rows and columns of the rectangular grid is about one-half of the wavelength of the microwave radiation.

11. The reflect array of claim 8, wherein:

the elements of the second array are disposed in the interstitial spaces along the rows and columns of the rectangular grid.

12. The reflect array of claim 1, wherein:

for each pair of adjacent phasing elements in the first array, a single one of the phasing elements in the second array is located between those adjacent phasing elements in the first array.

13. The reflect array of claim 12, wherein, for each phasing element in the second array that is located between adjacent phasing elements in the first array:

a first portion of that phasing element in the second array lies between portions of one neighboring phasing element in the first array; and

a second portion of that phasing element in the second array lies between portions of another neighboring phasing element in the first array.

14. A system comprising:

a microwave energy source configured to generate microwave energy in a predetermined frequency band; and

a beam director configured to direct the microwave energy received from the microwave energy source, the beam director including a reflect array, the reflect array comprising;

a dielectric substrate having a first surface and a second surface;

a continuous conductive layer on the second surface; and

a first array of phasing elements and a second array of phasing elements interleaved in a single layer on the first surface, the elements of the first array having a first shape and the elements of the second array having a second shape different from the first shape;

wherein the first array and the second array are collectively configured to reflect the microwave energy in the predetermined frequency band to provide a reflected beam, the reflected beam having a phase shift relative to the received microwave energy determined, at least in part, by dimensions of the elements of both the first and second arrays of phasing elements; and

wherein a spacing between adjacent elements of the second array is substantially equal to a spacing between adjacent elements in the first array.

15. The system of claim 14, wherein the phase shift at any point within an extent of the reflect array can be set to any value within a continuous range spanning more than 315 degrees by setting dimensions of the phasing elements in the first and second arrays.

16. The system of claim 15, wherein the phase shift at any point within the extent of the reflect array can be set to any value within a continuous range spanning more than 355 degrees by setting the dimensions of the phasing elements in the first and second arrays.

17. The system of claim 14, wherein:

for each pair of adjacent phasing elements in the first array, a single one of the phasing elements in the second array is located between those adjacent phasing elements in the first array; and

for each phasing element in the second array that is located between adjacent phasing elements in the first array;

a first portion of that phasing element in the second array lies between portions of one neighboring phasing element in the first array; and

a second portion of that phasing element in the second array lies between portions of another neighboring phasing element in the first array.

18. A method comprising:

receiving microwave energy in a predetermined frequency band; and

forming the microwave energy into a reflected beam with a beam director, the beam director including a reflect array, the reflect array comprising;

a dielectric substrate having a first surface and a second surface;

a continuous conductive layer on the second surface; and

a first array of phasing elements and a second array of phasing elements interleaved in a single layer on the first surface, the elements of the first array having a first shape and the elements of the second array having a second shape different from the first shape;

wherein the first array and the second array are collectively configured to reflect the microwave energy in the predetermined frequency band to provide the reflected beam, the reflected beam having a phase shift relative to the received microwave energy determined, at least in part, by dimensions of the elements of both the first and second arrays of phasing elements; and

wherein a spacing between adjacent elements of the second array is substantially equal to a spacing between adjacent elements in the first array.

19. The method of claim 18, wherein the phase shift at any point within an extent of the reflect array can be set to any value within a continuous range spanning more than 315 degrees by setting dimensions of the phasing elements in the first and second arrays.

20. The method of claim 19, wherein the phase shift at any point within the extent of the reflect array can be set to any value within a continuous range spanning more than 355 degrees by setting the dimensions of the phasing elements in the first and second arrays.