Horn antenna array

• US 10,658,760 B2
• Filed: 06/26/2018
• Issued: 05/19/2020
• Est. Priority Date: 06/26/2017
• Status: Active Grant

• Current Assignee: Nidec Elesys Corporation (Nidec Corporation), Wgr Co., Ltd.
• Original Assignee: Nidec Corporation
• Inventors: Kamo, Hiroyuki, Kirino, Hideki
• Primary Examiner(s): Mai, Lam T
• Application Number:
  US16/018,160
• Publication Number:
  US 20180375218A1
• Time in Patent Office: 693 Days
• Field of Search: 343702, 343786, 343753, 343776
• CPC Class Codes: H01Q 13/0233 Horns fed by a slotted waveguide array biconical horns H01Q13/06
• CPC Class Codes: H01Q 13/025 Multimode horn antennas; Horns using higher mode of propagation H01Q13/0241 takes precedence; multiple beam H01Q25/04
• CPC Class Codes: H01Q 13/0283 Apparatus or processes specially provided for manufacturing horns
• CPC Class Codes: H01Q 21/0087 Apparatus or processes specially adapted for manufacturing antenna arrays manufacturing waveguides H01P11/00
• CPC Class Codes: H01Q 21/064 using horn or slot aerials slotted waveguides arrays H01Q21/005

Abstract

A horn antenna array includes at least two horn antenna elements arranged along a first direction. Each of the at least two horn antenna elements includes a base having a slot extending along a second direction which intersects the first direction, and a horn communicating with the slot, the horn having a pair of electrically-conductive first inner walls intersecting the first direction and a pair of electrically-conductive second inner walls intersecting the second direction. The pair of second inner walls include a pair of opposing protrusions. When radiating an electromagnetic wave, the pair of protrusions create two radiation sources on the inside of the pair of first inner walls.

Claims

1. A horn antenna array comprising at least two horn antenna elements arranged along a first direction, wherein,

each of the at least two horn antenna elements includes

a base having a slot extending along a second direction which intersects the first direction, and

a horn communicating with the slot, the horn having a pair of electrically-conductive first inner walls intersecting the first direction and a pair of electrically-conductive second inner walls intersecting the second direction;

and

the pair of second inner walls each include a protrusion, the protrusions defining a pair of opposing protrusions.

2. The horn antenna array of claim 1, wherein

the pair of first inner walls each include a ridge portion, the ridge portions defining a pair of opposing ridge portions;

the pair of ridge portions protrude toward a center axis of the horn respectively from the pair of first inner walls; and

an interval between the pair of ridge portions increases away from the slot.

3. The horn antenna array of claim 2, wherein, as viewed from a direction of one of the pair of second inner walls, a foremost edge of each of the pair of ridge portions has a concave shape with respect to the center axis.

4. The horn antenna array of claim 1, wherein a foremost edge of the pair of protrusions has a convex shape.

5. The horn antenna array of claim 3, wherein a foremost edge of the pair of protrusions has a convex shape.

6. The horn antenna array of claim 1, wherein at front-side edges of the pair of second inner walls, the pair of protrusions are located in central portions thereof.

7. The horn antenna array of claim 5, wherein at front-side edges of the pair of second inner walls, the pair of protrusions are located in central portions thereof.

8. The horn antenna array of claim 2, wherein the slot includes a lateral portion extending along the second direction and a pair of vertical portions extending along a third direction from opposite ends of the lateral portion, the third direction intersecting the second direction.

9. The horn antenna array of claim 3, wherein the slot includes a lateral portion extending along the second direction and a pair of vertical portions extending along a third direction from opposite ends of the lateral portion, the third direction intersecting the second direction.

10. The horn antenna array of claim 5, wherein the slot includes a lateral portion extending along the second direction and a pair of vertical portions extending along a third direction from opposite ends of the lateral portion, the third direction intersecting the second direction.

11. The horn antenna array of claim 1, wherein,

the horn antenna array is used to radiate an electromagnetic wave of a band having a central wavelength λ

o in free space;

the horn antenna array includes a plurality of horn antenna elements which are arranged in a two-dimensional array along the first direction and the second direction;

a period of arrangement of the plurality of horn antenna elements along the first direction is greater than λ

o; and

a period of arrangement of the plurality of horn antenna elements along the second direction is smaller than λ

o.

12. The horn antenna array of claim 2, wherein,

the horn antenna array is used to radiate an electromagnetic wave of a band having a central wavelength λ

o in free space;

the horn antenna array includes a plurality of horn antenna elements which are arranged in a two-dimensional array along the first direction and the second direction;

a period of arrangement of the plurality of horn antenna elements along the first direction is greater than λ

o; and

a period of arrangement of the plurality of horn antenna elements along the second direction is smaller than λ

o.

13. The horn antenna array of claim 3, wherein,

the horn antenna array is used to radiate an electromagnetic wave of a band having a central wavelength λ

o in free space;

the horn antenna array includes a plurality of horn antenna elements which are arranged in a two-dimensional array along the first direction and the second direction;

a period of arrangement of the plurality of horn antenna elements along the first direction is greater than λ

o and smaller than 2λ

o; and

a period of arrangement of the plurality of horn antenna elements along the second direction is smaller than λ

o.

14. The horn antenna array of claim 1, wherein a dimension of the horn along the first direction is greater than a dimension of the horn along the second direction.

15. The horn antenna array of claim 2, wherein a dimension of the horn along the first direction is greater than a dimension of the horn along the second direction.

16. The horn antenna array of claim 9, wherein

the horn antenna array is used to radiate an electromagnetic wave of a band having a central wavelength λ

o in free space;

a dimension of the horn along the first direction is greater than a dimension of the horn along the second direction; and

the period of arrangement of the at least two horn antenna elements is smaller than 2λ

o.

17. The horn antenna array of claim 1 which is formed by injection molding or die casting.

18. The horn antenna array of claim 10 which is formed by injection molding or die casting.

19. The horn antenna array of claim 1, further comprising:

a plate-shaped first electrically conductive member having a front-side first electrically conductive surface and a rear-side second electrically conductive surface, the first electrically conductive surface having a shape which defines the respective slots and horns of the horn antenna elements;

a second electrically conductive member having a third electrically conductive surface opposing the second electrically conductive surface;

a waveguide member located between the first electrically conductive member and the second electrically conductive member and extending along the first direction, the waveguide member having an electrically-conductive waveguide face opposing the second electrically conductive surface or the third electrically conductive surface; and

an artificial magnetic conductor extending on both sides of the waveguide member, wherein,

a waveguide is constituted by the waveguide face and the second electrically conductive surface or the third electrically conductive surface opposing the waveguide face; and

the slot is coupled to the waveguide.

20. The horn antenna array of claim 10, further comprising:

a plate-shaped first electrically conductive member having a front-side first electrically conductive surface and a rear-side second electrically conductive surface, the first electrically conductive surface having a shape which defines the respective slots and horns of the horn antenna elements;

a second electrically conductive member having a third electrically conductive surface opposing the second electrically conductive surface;

a waveguide member located between the first electrically conductive member and the second electrically conductive member and extending along the first direction, the waveguide member having an electrically-conductive waveguide face opposing the second electrically conductive surface or the third electrically conductive surface; and

an artificial magnetic conductor extending on both sides of the waveguide member, wherein,

a waveguide is constituted by the waveguide face and the second electrically conductive surface or the third electrically conductive surface opposing the waveguide face;

the slot is coupled to the waveguide; and

at front-side edges of the pair of second inner walls, the pair of protrusions are located in central portions thereof.

21. The horn antenna array of claim 17, further comprising:

a plate-shaped first electrically conductive member having a front-side first electrically conductive surface and a rear-side second electrically conductive surface, the first electrically conductive surface having a shape which defines the respective slots and horns of the horn antenna elements;

a second electrically conductive member having a third electrically conductive surface opposing the second electrically conductive surface;

a waveguide member located between the first electrically conductive member and the second electrically conductive member and extending along the first direction, the waveguide member having an electrically-conductive waveguide face opposing the second electrically conductive surface or the third electrically conductive surface; and

an artificial magnetic conductor extending on both sides of the waveguide member, wherein,

a waveguide is constituted by the waveguide face and the second electrically conductive surface or the third electrically conductive surface opposing the waveguide face;

the slot is coupled to the waveguide; and

for each of the horns, a dimension of the horn along the first direction is greater than a dimension of the horn along the second direction.

22. A radar device comprising:

the horn antenna array of claim 20; and

a microwave integrated circuit, wherein

the microwave integrated circuit is coupled to the waveguide via at least another waveguide member.

23. A radar device comprising:

the horn antenna array of claim 1; and

a microwave integrated circuit, wherein

the microwave integrated circuit is coupled to the horn antenna array via at least one waveguide.

24. A radar device comprising:

the horn antenna array of claim 17; and

a microwave integrated circuit, wherein

the microwave integrated circuit is coupled to the horn antenna array via at least one waveguide.

25. A horn antenna array comprising at least two horn antenna elements arranged along a first direction, wherein,

each of the at least two horn antenna elements includes

a base having a feeding portion to supply an electromagnetic wave having an magnetic field whose direction is a second direction intersecting the first direction, and

a horn to be fed from the feeding portion, the horn having a pair of electrically-conductive first inner walls intersecting the first direction and a pair of electrically-conductive second inner walls intersecting the second direction;

and

the pair of second inner walls each include a protrusion, the protrusions defining a pair of opposing protrusions.

26. The horn antenna array of claim 25, wherein,

the pair of protrusions create a first radiation source with one of the pair of first inner walls and a second radiation source with another of the pair of first inner walls;

the horn antenna array is used to radiate an electromagnetic wave of a band having a central wavelength λ

o in free space;

a period of arrangement of the at least two horn antenna elements is greater than λ

o; and

an interval between the first radiation source and the second radiation source is smaller than λ

o.

27. The horn antenna array of claim 26, wherein the period of arrangement of the at least two horn antenna elements is smaller than 2λ

o.

28. The horn antenna array of claim 25, wherein a dimension of the horn along the first direction is greater than a dimension of the horn along the second direction.

29. The horn antenna array of claim 27 which is formed by injection molding or die casting.

30. The horn antenna array of claim 25, further comprising:

a plate-shaped first electrically conductive member having a front-side first electrically conductive surface and a rear-side second electrically conductive surface, the first electrically conductive surface having a shape which defines the respective slots and horns of the horn antenna elements;

a second electrically conductive member having a third electrically conductive surface opposing the second electrically conductive surface;

a waveguide member located between the first electrically conductive member and the second electrically conductive member and extending along the first direction, the waveguide member having an electrically-conductive waveguide face opposing the second electrically conductive surface or the third electrically conductive surface; and

an artificial magnetic conductor extending on both sides of the waveguide member, wherein,

a waveguide is constituted by the waveguide face and the second electrically conductive surface or the third electrically conductive surface opposing the waveguide face; and

the slot is coupled to the waveguide.

31. A radar device comprising:

the horn antenna array of claim 29; and

a microwave integrated circuit, wherein

the microwave integrated circuit is coupled to the waveguide via at least another waveguide member.