Broadband antenna unit comprising a folded plate-shaped monopole antenna portion and an extending portion

• US 20080198075A1
• Filed: 02/08/2008
• Published: 08/21/2008
• Est. Priority Date: 02/20/2007
• Status: Active Grant

• Current Assignee: Mitsumi Electric Co., Ltd. (Minebea Mitsumi, Inc.)
• Original Assignee: Mitsumi Electric Co., Ltd. (Minebea Mitsumi, Inc.)
• Inventors: Yoshioka, Hiroki
• Granted Patent: US 8,081,116 B2
• Time in Patent Office: Days
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 5/25 Ultra-wideband [UWB] systems, e.g. multiple resonance systems; Pulse systems
• CPC Class Codes: H01Q 5/364 Creating multiple current paths
• CPC Class Codes: H01Q 9/40 Element having extended radiating surface
• CPC Class Codes: H01Q 9/42 with folded element, the folded parts being spaced apart a small fraction of the operating wavelength

Abstract

In a broadband antenna unit including a ground plate, an antenna element disposed in the vicinity of an end of the ground plate, and a dielectric substrate for mounting the antenna element therein, the antenna element includes a folded plate-shaped monopole antenna portion having a U-shape in cross section and an extending portion extending from the folded plate-shaped monopole antenna portion. The antenna element is disposed on the side of one side edge of the ground plate. The broadband antenna unit has a feeding point between the ground plate and the antenna element that is disposed at a feeding position apart from the one side by a predetermined distance. A ratio between a width of the ground plate and the predetermined distance is substantially 5:2 when a ratio between the width of the ground plate and a width of the folded plate-shaped monopole antenna portion is 2:1.

Claims

1. An antenna element comprising:

a folded plate-shaped monopole antenna portion having a U-shape in cross section; and

an extending portion extending from said folded plate-shaped monopole antenna portion.

2. The antenna element as claimed in claim 1, wherein said folded plate-shaped monopole antenna comprises:

a first conductive plate;

a second conductive plate disposed in parallel with said first conductive plate; and

a coupling plate for coupling said first conductive plate with said second conductive plate at an end portion thereof,

wherein said extending portion extends from said coupling plate.

3. The antenna element as claimed in claim 2, wherein said extending portion comprises:

a first extending portion in an extending direction where said coupling plate extends; and

a second extending portion which is bent at a tip of said first extending portion in a direction at right angles to said first extending portion.

4. The antenna element as claimed in claim 2, wherein said extending portion comprises only a first extending portion in an extending direction where said coupling plate extends.

5. The antenna element as claimed in claim 2, wherein said extending portion comprises:

a first extending portion in an extending direction where said coupling plate extends;

a second extending portion which is bent at a tip of said first extending portion in a direction at right angles to said first extending portion; and

a third extending portion which is bent at a tip of said second extending portion inwards in a direction at right angles to said second extending portion.

6. The antenna element as claimed in claim 1, wherein said folded plate-shaped monopole antenna portion and said extending portion have rounded edges.

7. The antenna element as claimed in claim 1, wherein said folded plate-shaped monopole antenna portion comprises:

a first conductive plate having a first length;

a second conductive plate which is disposed in parallel with said first conductive plate and which has a second length shorter than the first length; and

a coupling plate for coupling said first conductive plate with said second conductive plate at a first end portion thereof,

wherein said extending portion extends from any one of said first extending portion, said second extending portion, and said coupling plate.

8. The antenna element as claimed in claim 7, said folded plate-shaped monopole antenna portion having first and second side edges opposite to each other, wherein said first conductive plate has a notch at a tip portion thereof on the side of the first side edge.

9. The antenna element as claimed in claim 8, wherein said extending portion comprises:

a first extending portion which extends from the second side edge of a tip portion of said second conductive plate in an extending direction where said second conductive plate extends in a longitudinal direction of said second conductive plate;

a second extending portion which is bent from a tip of said first extending portion in a direction at right angles to said first extending portion toward the first end portion on the extending surface where said second conductive plate extends; and

a third extending portion which is bent from a tip of said second extending portion in a direction at right angles to said second extending portion and which extends nearer to said coupling plate on an extending surface where said coupling plate extends.

10. The antenna element as claimed in claim 8, wherein said extending portion comprises:

a first extending portion which extends from the second side edge of a tip portion of said first conductive plate on an extending plane where said first conductive plate extends in parallel with the second side edge of said first conductive plate and apart from the second side edge by a predetermined distance; and

a second extending portion which is bent from a tip of said first extending portion in the vicinity of said first end portion in a direction at right angles to said first extending portion and which extends away from said coupling plate on an extending plane where said first conductive plate extends.

11. The antenna element as claimed in claim 8, wherein said extending portion extends from the second side edge of said coupling plate on an extending plane where said coupling plate extends in a longitudinal direction of said coupling plate.

12. The antenna element as claimed in claim 8, wherein said extending portion extends from the second side edge of a tip portion of said second conductive plate on an extending plane where said second conductive plate extends in a longitudinal direction of said second conductive plate.

13. The antenna element as claimed in claim 8, wherein said extending portion extends from the first side edge of a tip portion of said first conductive plate on an extending plane where said first conductive plate extends in a longitudinal direction of said first conductive plate.

14. The antenna element as claimed in claim 8, wherein said extending portion extends from the first side edge of said coupling plate on an extending plane where said coupling plate extends in a longitudinal direction of said coupling plate.

15. The antenna element as claimed in claim 8, wherein said extending portion extends from the first side edge of a tip portion of said second conductive plate on an extending plane where said second conductive plate extends in a longitudinal direction of said second conductive plate.

16. A broadband antenna unit comprising:

a ground plate;

an antenna element disposed in the vicinity of an end of said ground plate; and

a dielectric substrate for mounting said antenna element thereon,

wherein said antenna element comprises a folded plate-shaped monopole antenna portion having a U-shape in cross section and an extending portion extending from said folded plate-shaped monopole antenna portion.

17. The broadband antenna unit as claimed in claim 16, wherein said antenna element is disposed on the side of one side edge of said ground plate,

wherein said broadband antenna unit has a feeding point between said ground plate and said antenna element that is located at a feeding position apart from said one side edge by a predetermined distance.

18. The broadband antenna unit as claimed in claim 17, wherein a ratio between a width of said ground plate and said predetermined distance is substantially 5:

2 when a ratio between the width of said ground plate and a width of said folded plate-shaped monopole antenna portion is 2;

1.

19. The broadband antenna unit as claimed in claim 16, wherein said folded plate-shaped monopole antenna comprises:

a first conductive plate;

a second conductive plate disposed in parallel with said first conductive plate; and

a coupling plate for coupling said first conductive plate with said second conductive plate at a first end portion away from said ground plate,

wherein said extending portion extends from said coupling plate.

20. The broadband antenna unit as claimed in claim 19, wherein said extending portion comprises:

a first extending portion which extends in an extending direction where said coupling plate extends; and

a second extending portion which is bent at a tip of said first extending portion in a direction at right angles to said first extending portion toward said ground plate.

21. The broadband antenna unit as claimed in claim 19, wherein said extending portion comprises only a first extending portion which extends in an extending direction where said coupling plate extends.

22. The broadband antenna unit as claimed in claim 19, wherein said extending portion comprises:

a first extending portion which extends in an extending direction where said coupling plate extends;

a second extending portion which is bent at a tip of said first extending portion in a direction at right angles to said first extending portion toward said ground plate; and

a third extending portion which is bent at a tip of said second extending portion in a direction at right angles to said second extending portion inwards.

23. The broadband antenna unit as claimed in claim 16, wherein said folded plate-shaped monopole antenna portion and said extending portion have rounded edges.

24. The broadband antenna unit as claimed in claim 16, wherein said folded plate-shaped monopole antenna portion comprises:

a first conductive plate having a first length;

a second conductive plate which is disposed in parallel with said first conductive plate and which has a second length shorter than the first length; and

a coupling plate for coupling said first conductive plate with said second conductive plate at a first end portion away from said ground plate,

wherein said extending portion extends from any one of said first extending portion, said second extending portion, and said coupling plate.

25. The broadband antenna unit as claimed in claim 24, said folded plate-shape monopole antenna portion having first and second side edges opposite to each other, wherein said first conductive plate has a notch at a tip portion thereof on the side of the first side edge.

26. The broadband antenna unit as claimed in claim 25, wherein said extending portion comprises:

a first extending portion which extends from the second side edge of a tip portion of said second conductive plate in an extending direction where said second conductive plate extends in a longitudinal direction of said second conductive plate;

a second extending portion which is bent from a tip of said first extending portion in a direction at right angles to said first extending portion toward the first end portion on the extending surface where said second conductive plate extends; and

a third extending portion which is bent from a tip of said second extending portion in a direction at right angles to said second extending portion and which extends nearer to said coupling plate on an extending surface where said coupling plate extends.

27. The broadband antenna unit as claimed in claim 25, wherein said extending portion comprises:

a first extending portion which extends from the second side edge of a tip portion of said first conductive plate on an extending plane where said first conductive plate extends in parallel with the second side edge of said first conductive plate and apart from the second side edge by a predetermined distance; and

a second extending portion which is bent from a tip of said first extending portion in the vicinity of said first end portion in a direction at right angles to said first extending portion and which extends away from said coupling plate on an extending plane where said first conductive plate extends.

28. The broadband antenna unit as claimed in claim 25, wherein said extending portion extends from the second side edge of said coupling plate on an extending plane where said coupling plate extends in a longitudinal direction of said coupling plate.

29. The broadband antenna unit as claimed in claim 25, wherein said extending portion extends from the second side edge of a tip portion of said second conductive plate on an extending plane where said second conductive plate extends in a longitudinal direction of said second conductive plate.

30. The broadband antenna unit as claimed in claim 25, wherein said extending portion extends from the first side edge of a tip portion of said first conductive plate on an extending plane where said first conductive plate extends in a longitudinal direction of said first conductive plate.

31. The broadband antenna unit as claimed in claim 25, wherein said extending portion extends from the first side edge of said coupling plate on an extending plane where said coupling plate extends in a longitudinal direction of said coupling plate.

32. The broadband antenna unit as claimed in claim 25, wherein said extending portion extends from the first side edge of a tip portion of said second conductive plate on an extending plane where said second conductive plate extends in a longitudinal direction of said second conductive plate.

33. A broadband antenna unit comprising:

a first ground plate;

a second ground plate;

an antenna element disposed between said first ground plate and said second ground plate in the vicinity of an end of said ground plate; and

a dielectric substrate for mounting said antenna element thereon,

wherein said antenna element comprises;

a folded plate-shaped monopole antenna portion having a U-shape in cross section; and

an extending portion extending from said folded plate-shaped monopole antenna portion.

34. The broadband antenna unit as claimed in claim 33, wherein said antenna element is disposed on the side of one side edge of said first ground plate,

wherein said broadband antenna unit has a feeding point between said first ground plate and said antenna element that is located at a feeding position apart from said one side edge by a predetermined distance.

35. The broadband antenna unit as claimed in claim 34, wherein a ratio between a width of said ground plate and said predetermined distance is substantially 5:

2 when a ratio between the width of said ground plate and a width of said folded plate-shaped monopole antenna portion is 2;

1.

36. The broadband antenna unit as claimed in claim 33, wherein said folded plate-shaped monopole antenna comprises:

a first conductive plate;

a second conductive plate disposed in parallel with said first conductive plate; and

a coupling plate for coupling said first conductive plate with said second conductive plate at a first end portion away from said ground plate,

wherein said extending portion extends from said coupling plate.

37. The broadband antenna unit as claimed in claim 36, wherein said extending portion comprises:

a first extending portion which extends in an extending direction where said coupling plate extends; and

a second extending portion which is bent at a tip of said first extending portion in a direction at right angles to said first extending portion toward said first ground plate.

38. The broadband antenna unit as claimed in claim 36, wherein said extending portion comprises only a first extending portion which extends in an extending direction where said coupling plate extends.

39. The broadband antenna unit as claimed in claim 36, wherein said extending portion comprises:

a first extending portion which extends in an extending direction where said coupling plate extends;

a second extending portion which is bent at a tip of said first extending portion in a direction at right angles to said first extending portion toward said first ground plate; and

a third extending portion which is bent at a tip of said second extending portion in a direction at right angles to said second extending portion inwards.

40. The broadband antenna unit as claimed in claim 33, wherein said folded plate-shaped monopole antenna portion and said extending portion have rounded edges.

41. The broadband antenna unit as claimed in claim 33, wherein said folded plate-shaped monopole antenna portion comprises:

a first conductive plate having a first length;

a second conductive plate which is disposed in parallel with said first conductive plate and which has a second length shorter than the first length; and

a coupling plate for coupling said first conductive plate with said second conductive plate at a first end portion away from said first ground plate,

wherein said extending portion extends from any one of said first extending portion, said second extending portion, and said coupling plate.

42. The broadband antenna unit as claimed in claim 41, said folded plate-shape monopole antenna portion having first and second side edges opposite to each other, wherein said first conductive plate has a notch at a tip portion thereof on the side of the first side edge.

43. The broadband antenna unit as claimed in claim 42, wherein said extending portion comprises:

a first extending portion which extends from the second side edge of a tip portion of said second conductive plate in an extending direction where said second conductive plate extends in a longitudinal direction of said second conductive plate;

a second extending portion which is bent from a tip of said first extending portion in a direction at right angles to said first extending portion toward the first end portion on the extending surface where said second conductive plate extends; and

a third extending portion which is bent from a tip of said second extending portion in a direction at right angles to said second extending portion and which extends nearer to said coupling plate on an extending surface where said coupling plate extends.

44. The broadband antenna unit as claimed in claim 42, wherein said extending portion comprises:

a first extending portion which extends from the second side edge of a tip portion of said first conductive plate on an extending plane where said first conductive plate extends in parallel with the second side edge of said first conductive plate and apart from the second side edge by a predetermined distance; and

a second extending portion which is bent from a tip of said first extending portion in the vicinity of said first end portion in a direction at right angles to said first extending portion and which extends away from said coupling plate on an extending plane where said first conductive plate extends.

45. The broadband antenna unit as claimed in claim 42, wherein said extending portion extends from the second side edge of said coupling plate on an extending plane where said coupling plate extends in a longitudinal direction of said coupling plate.

46. The broadband antenna unit as claimed in claim 42, wherein said extending portion extends from the second side edge of a tip portion of said second conductive plate on an extending plane where said second conductive plate extends in a longitudinal direction of said second conductive plate.

47. The broadband antenna unit as claimed in claim 42, wherein said extending portion extends from the first side edge of a tip portion of said first conductive plate on an extending plane where said first conductive plate extends in a longitudinal direction of said first conductive plate.

48. The broadband antenna unit as claimed in claim 42, wherein said extending portion extends from the first side edge of said coupling plate on an extending plane where said coupling plate extends in a longitudinal direction of said coupling plate.

49. The broadband antenna unit as claimed in claim 42, wherein said extending portion extends from the first side edge of a tip portion of said second conductive plate on an extending plane where said second conductive plate extends in a longitudinal direction of said second conductive plate.