Internal antenna and methods

• US 20090140942A1
• Filed: 04/11/2008
• Published: 06/04/2009
• Est. Priority Date: 10/10/2005
• Status: Active Grant

• Current Assignee: Cantor Fitzgerald Securities (Cantor Fitzgerald, L.P.)
• Original Assignee: Pulse Finland Oy (Yageo Corporation)
• Inventors: Mikkola, Jyrki, Nissinen, Pertti, Raappana, Ari, Keskitalo, Pasi
• Granted Patent: US 7,903,035 B2
• Time in Patent Office: Days
• US Class Current: 343/767
• CPC Class Codes: H01Q 1/243 with built-in antennas
• CPC Class Codes: H01Q 1/36 Structural form of radiating elements, e.g. cone, spiral, umbrella; Particular materials used therewithH01Q1/08, H01Q1/14 take precedence
• CPC Class Codes: H01Q 1/38 formed by a conductive layer on an insulating support patch antennas H01Q9/0407; microstrip dipole antennas H01Q9/065; microstrip slot antennas H01Q13/106; transmission line microstrip antennas H01Q13/206; manufacturing reflecting surfaces using insulating material for supporting the reflecting surface H01Q15/142
• CPC Class Codes: H01Q 5/371 Branching current paths
• CPC Class Codes: H01Q 9/0442 with particular tuning means

Abstract

An internal antenna especially aimed at flat radio devices. The antenna (200) comprises a planar radiator (220) with a branch (221) for forming a lower operating band for the antenna and a second branch (222) for forming an upper operating band. The branches typically form a frame-like pattern. There remains a slot (230) between the branches, opening to the outer edge of the radiator approximately in the middle of the edge running in the direction of the end of the circuit board (205) and being outside the circuit board as seen from above. The omnidirectional radiation of the antenna on its upper operating band improves as compared to the corresponding, known antennas, and its efficiency improves, because the average antenna gain increases.

Claims

1-9. -9. (canceled)

10. Antenna apparatus useful in a radio device comprising a substrate having a ground plane thereon, said antenna comprising:

a feed point;

a substantially planar monopole radiator comprising a first branch for a lower operating band of the antenna and a second branch for an upper operating band of the antenna; and

a slot opening to an outer edge of the substantially planar monopole radiator, said slot opening being disposed in a generally centralized area of said radiator, said slot residing substantially between said first and second branches.

11. The antenna apparatus of claim 10, wherein said outer edge is disposed substantially parallel with an end of the substrate.

12. The antenna apparatus of claim 11, wherein said generally centralized area comprises a 40 percent middle portion of said outer edge.

13. The antenna apparatus of claim 12, wherein said outer edge comprises a first and a second section at least partly demarcated by said slot opening, said first and second sections being substantially collinear with respect to one another.

14. The antenna apparatus of claim 10, further comprising a tuning branch.

15. The antenna apparatus of claim 10, wherein said first and second branches define a generally rectangular outer perimeter and a central aperture.

16. The antenna apparatus of claim 15, wherein at least one of said first and second branches protrudes into said central aperture forming a branch protrusion.

17. The antenna apparatus of claim 16, wherein said branch protrusion comprises a generally L-shaped branch section.

18. The antenna apparatus of claim 10, wherein said slot opening disposed in said generally centralized area improves the omnidirectional radiation characteristics of the antenna apparatus in at least one operating band.

19. The antenna apparatus of claim 12, wherein said outer edge comprises a first and a second section at least partly demarcated by said slot opening, said first and second sections being substantially parallel, yet non-collinear, with respect to one another.

20. The antenna apparatus of claim 10, wherein said feed point is disposed generally at a region of intersection of said first and second branches.

21. The antenna apparatus of claim 10, wherein said feed point is disposed proximate a region of intersection of said first and second branches.

22. The antenna apparatus of claim 10, wherein said first and second branches comprise differing lengths with respect to one another, said differing lengths corresponding to differing operating bands for said antenna apparatus.

23. A portable radio device comprising an omnidirectional planar monopole antenna, said radio device further comprising:

a processor adapted to process received electromagnetic signals;

a substrate comprising a ground plane, said substrate further adapted to electrically couple said processor with said omnidirectional planar monopole antenna;

wherein said omnidirectional planar monopole antenna comprises;

a feed point;

a planar monopole radiator comprising a first branch for a lower operating band of the antenna and a second branch for an upper operating band of the antenna; and

a slot opening to an outer edge of the planar monopole radiator in a generally centralized area of said planar monopole radiator, said slot residing substantially between said first and second branches; and

wherein said outer edge is disposed substantially parallel with an end of the substrate.

24. The radio device of claim 23, wherein said processor comprises a microprocessor adapted for global positioning system applications.

25. The radio device of claim 23, wherein said ground plane resides outside of the footprint of said omnidirectional planar monopole antenna.

26. The radio device of claim 25, wherein said outer edge of the planar monopole radiator is located outside of said substrate outer edge when viewed from above.

27. The radio device of claim 23, wherein said first and second branches define a generally rectangular outer perimeter and a central aperture.

28. The radio device of claim 27, wherein at least one of said first and second branches protrudes into said central aperture forming a branch protrusion.

29. The radio device of claim 23, wherein said generally centralized area comprises a central 40 percent portion of said outer edge.

30. The radio device of claim 23, wherein said first and second branches comprise differing lengths with respect to one another, said differing lengths corresponding to differing operating bands for said antenna apparatus.

31. An internal antenna of a radio device, the radio device having a circuit board provided with a ground plane, said antenna comprising:

a planar monopole radiator, which is divided, as seen from a feed point of the antenna, into a first branch to form a lower operating band for the antenna, and a second branch to form an upper operating band for the antenna, wherein between said branches there remains a slot opening to an outer edge of the radiator, characterized in that said outer edge is the edge of the radiator running substantially in the direction of an end of the circuit board and outside the circuit board as seen from above, and wherein said slot opens to the outer edge in its central area to improve the omnidirectional radiation of the antenna on its upper operating band.

32. An antenna according to claim 31, characterized in that said radiator is located substantially in the same geometrical plane as the circuit board of the radio device.

33. An antenna according to claim 31, characterized in that said radiator is elevated from the circuit board of the radio device, partly on top of the ground plane.

34. An antenna according to claim 32, characterized in that said radiator is located at least partly on top of the ground plane.

35. An antenna according to claim 31, characterized in that it further comprises a radiating parasitic element located at least partly below said radiator and connected at one point thereof to the ground plane of at least one of the radio device or the signal ground.

36. An antenna according to claim 31, characterized in that the first branch has an end portion located in a central area of the radiator proximate the free end of the second branch so as to set said operating bands at the desired places in the frequency scale.

37. An antenna according to claim 31, characterized in that said radiator comprises a strip of metal sheet.

38. An antenna according to claim 31, characterized in that said slot opens to the outer edge of the radiator substantially perpendicularly to the end of the circuit board.

39. An antenna according to claim 31, characterized in that said slot opens to the outer edge of the radiator in the direction of the end of the circuit board.

40. An internal antenna for use in a radio device, comprising:

a substantially planar radiator comprising a first branch for forming a lower operating band for the antenna and a second branch for forming an upper operating band;

a slot formed at least partly between the branches, opening to the outer edge of the radiator;

wherein radiation from said antenna in said upper band is substantially omnidirectional in the horizontal plane when the radiator is in an upright position with respect to said horizontal plane so that a ground plane of the radio device remains below said horizontal plane.

41. A high-efficiency internal antenna for use in a radio device, comprising:

a substantially planar radiator comprising a first branch for forming a lower operating band for the antenna and a second branch for forming an upper operating band;

a slot formed at least partly between the branches, opening to the outer edge of the radiator;

wherein radiation from said antenna in said upper band is substantially equal within a dimension, said dimension being oriented in the direction of said outer edge.

42. The antenna of claim 41, wherein said high efficiency results at least from an average antenna gain increase over a gain otherwise achievable with other antenna configurations not having said first branch, said second branch, and said slot.