REFLECT ARRAY

• US 20100220036A1
• Filed: 09/30/2009
• Published: 09/02/2010
• Est. Priority Date: 09/30/2008
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: CHEN, Qiang, FURUNO, Tatsuo, UEBAYASHI, Shinji, YUAN, Qiaowei, LI, Long, SAWAYA, Kunio, MARUYAMA, Tamami
• Granted Patent: US 8,390,531 B2
• Time in Patent Office: Days
• US Class Current: 343/912
• CPC Class Codes: H01Q 3/46 Active lenses or reflecting arrays

Abstract

A reflect array (1) according to the present invention includes a plurality of array elements (10) forming an array configured to control a direction of a reflected wave (scattered wave) by controlling a phase of the reflected wave; and a ground plane (30). The ground plane (30) has a structure with a frequency selective function.

Claims

1. A reflect array comprising:

a plurality of array elements forming an array configured to control a direction of a reflected wave (scattered wave) by controlling a phase of the reflected wave; and

a ground plane, wherein

the ground plane has a structure with a frequency selective function.

6. The reflect array according to any one of claims 1, 4 and 5, wherein

the frequency selective structure has periodic structure loops.

7. The reflect array according to any one of claims 1, 4, 5 and 6, wherein

the frequency selective structure is configured to reflect (scatter) electric waves at a selective frequency, and to transmit electric waves at frequencies other than the selective frequency.

8. The reflect array according to any one of claims 1 to 7, wherein

the reflect array has a structure which enables the reflected wave to be tilted in a desired direction, by giving a phase difference between X direction and Y direction, for incidence from the X direction and incidence from the Y direction.

9. The reflect array according to any one of claims 6 and 8, wherein

each periodic structure loop has a desired frequency of 1 λ

; and

a pitch between the periodic structure loops is within a range between 0.4 λ and

0.6 λ

.

10. The reflect array according to any one of claims 1 to 9, wherein

each array element is formed so as to have the same structure and the same size when seen from the horizontal direction and the vertical direction.

11. The reflect array according to claim 10, wherein

the ground plane is formed so as to have the same structure and the same size when seen from the horizontal direction and the vertical direction.

2. A reflect array comprising:

a plurality of array elements forming an array configured to control a direction of a reflected wave (scattered wave) by controlling a phase of the reflected wave; and

a ground plane, wherein

the array elements have a structure for aligning phases for a TE incident wave and a structure for aligning phases for a TM incident wave.

4. The reflect array according to any one of claims 2 and 3, wherein

the reflect array has a frequency selective structure.

5. The reflect array according to any one of claims 2 to 4, wherein

each array element is formed of a crossed dipole having a horizontal rod and a vertical rod;

horizontal and vertical dimensions of the crossed dipole are different for each array element; and

for both a TE incident wave and a TM incident wave, any one of the horizontal and vertical rods is operated to control the phase of the reflected wave, thereby controlling the direction of the reflected wave for both of a TE wave and a TM wave simultaneously.

3. A reflect array comprising:

a plurality of array elements forming an array configured to control a direction of a reflected wave (scattered wave) by controlling a phase of the reflected wave; and

a ground plane, wherein

the array elements are polarization sharing elements and have a function capable of being shared and used for incident waves coming in as both horizontally-polarized and vertically-polarized waves.

12. A reflect array comprising:

a plurality of array elements; and

a ground plane, wherein

each array element is formed of a crossed dipole having a horizontal rod and a vertical rod; and

when an incidence direction of a vertically-polarized wave and an incidence direction of a horizontally-polarized wave are different from each other, the vertical rods are operated for the incidence of the vertically-polarized wave so that a reflected wave (scattered wave) is radiated in a direction determined by a phase of a current distribution of each vertical rod, and the horizontal rods are operated for the incidence of the horizontally-polarized wave so that a reflected wave (scattered wave) is radiated in a direction determined by a phase of a current distribution of each horizontal rod, thereby independently determining a radiation direction of the reflected wave of the vertically-polarized wave and a radiation direction of the reflected wave of the horizontally-polarized wave.

13. The reflect array according to claim 12, wherein

an operating frequency of the horizontal rod and an operating frequency of the vertical rod are different from each other.

14. The reflect array according to any one of claims 12 and 13, wherein

the ground plane is formed of a frequency selective surface.

15. The reflect array according to claim 14, wherein

the frequency selective surface is formed of a loop array.

16. The reflect array according to any one of claims 14 and 15, wherein

the ground plane is formed of a two-frequency-sharing frequency selective surface.

17. The reflect array according to any one of claims 14 and 15, wherein

the ground plane is formed of a broadband frequency selective surface.