Multiple band printed monopole antenna

• US 5,828,342 A
• Filed: 05/22/1997
• Issued: 10/27/1998
• Est. Priority Date: 06/02/1995
• Status: Expired due to Term

• Current Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Hayes, Gerard James, Lampe, Ross Warren
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): Ho, Tan
• Application Number:
  US08/859,938
• Time in Patent Office: 523 Days
• Field of Search: 343/700 MS, 343/702, 343/873, 343/749, 343/895, 343/720, 343/833, 343/835, 343/818
• US Class Current: 343/702
• 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 5/49 with parasitic elements used for purposes other than for dual-band or multi-band, e.g. imbricated Yagi antennas
• CPC Class Codes: H01Q 9/30 with feed to end of elongated active element, e.g. unipole H01Q9/44 takes precedence

Abstract

A printed monopole antenna is disclosed including a first printed circuit board having a first side and a second side, a first monopole radiating element in the form of a conductive trace formed on a side of the first printed circuit board, and a second monopole radiating element in the form of a conductive trace positioned adjacent the first monopole radiating element, wherein the first monopole radiating element is resonant within a first frequency band and the second monopole radiating element is resonant within a second frequency band. In order for the first and second radiating elements to be resonant within different frequency bands, the conductive traces for each have different electrical lengths. No direct electrical connection exists between the monopole radiating elements, but the second radiating element dominates at a frequency in which the second radiating element is approximately a half-wavelength so that coupling with the first radiating element occurs. The first and second monopole radiating elements are formed on the same side of the first printed circuit board, separate sides of the first printed circuit board, or on separate printed circuit boards.

Claims

1. A printed monopole antenna having a ground plane defined substantially perpendicular thereto and being operable within a first specified frequency band and a second specified frequency band, comprising:

(a) a first printed circuit board having a first side and a second side, said first printed circuit board lying in a plane substantially perpendicular to said ground plane;

(b) a first monopole radiating element comprising a first conductive trace formed on said first printed circuit board first side, said first conductive trace having a physical length from a feed end to an opposite end and a predetermined electrical length so that said first monopole radiating element is resonant within said first specified frequency band;

(c) a feed port including a signal feed portion and a ground portion, said signal feed portion being coupled only to said feed end of said first conductive trace; and

(d) a second monopole radiating element positioned adjacent to said first monopole radiating element and not connected to said feed port, said second monopole radiating element comprising a second conductive trace having a physical length from a first end to a second end and a predetermined electrical length so that said second monopole radiating element is resonant within said second specified frequency band, wherein said second conductive trace is electrically coupled to said first conductive trace so as to receive signals through said first conductive trace when said printed monopole antenna is operated within said second specified frequency band.

2. The printed monopole antenna of claim 1, wherein said second conductive trace is formed on said first printed circuit board first side.

3. The printed monopole antenna of claim 2, wherein said first conductive trace, said second conductive trace, and said first printed circuit board are overmolded with a dielectric material.

4. The printed monopole antenna of claim 1, wherein said first and second conductive traces are oriented substantially parallel to each other.

5. The printed monopole antenna of claim 1, wherein the physical lengths of said first and second conductive traces are substantially equivalent.

6. The printed monopole antenna of claim 1, wherein said first frequency band is approximately 800MegaHertz to approximately 1000 MegaHertz.

7. The printed monopole antenna of claim 1, wherein said second frequency band is approximately 1800MegaHertz to approximately 2000 MegaHertz.

8. The printed monopole antenna of claim 1, wherein said first conductive trace has an electrical length greater than said physical length of said first conductive trace.

9. The printed monopole antenna of claim 1, wherein said first conductive trace has an electrical length greater than an electrical length of said second conductive trace.

10. The printed monopole antenna of claim 1, wherein said second conductive trace has an electrical length substantially equivalent to said physical length of said second conductive trace.

11. The printed monopole antenna of claim 1, wherein said second conductive trace has an electrical length greater than said physical length of said second conductive trace.

12. The printed monopole antenna of claim 1, wherein said second conductive trace has an electrical length substantially equivalent to a half wavelength for a frequency within said second frequency band.

13. The printed monopole antenna of claim 1, wherein said first conductive trace has an electrical length substantially equivalent to a quarter wavelength for a frequency within said first frequency band.

14. The printed monopole antenna of claim 1, wherein said first conductive trace has an electrical length substantially equivalent to a half wavelength for a frequency within said first frequency band.

15. The printed monopole antenna of claim 1, wherein no direct electrical connection exists between said first and second monopole radiating elements.

16. The printed monopole antenna of claim 1, wherein said feed port comprises a coaxial connector.

17. The printed monopole antenna of claim 1, wherein said first printed circuit board is made of a flexible dielectric material.

18. The printed monopole antenna of claim 1, wherein said second monopole radiating element is not connected to ground.

19. A printed monopole antenna having a ground plane defined substantially perpendicular thereto and being operable within a first specified frequency band and a second specified frequency band, comprising;

(a) a first printed circuit board having a first side and a second side, said first printed circuit board lying in a plane substantially perpendicular to said ground plane;

(b) a first monopole radiating element comprising a first conductive trace formed on said first printed circuit board first side, said first conductive trace having a physical length from a feed end to an opposite end and a predetermined electrical length so that said first monopole radiating element is resonant within said first specified frequency band;

(c) a feed port including a signal feed portion and a ground portion, said signal feed portion being coupled only to said feed end of said first conductive trace; and

(d) a second monopole radiating element positioned adjacent to said first monopole radiating element and not connected to said feed port, said second monopole radiating element comprising a second conductive trace formed on said first printed circuit board second side having a physical length from a first end to a second end and a predetermined electrical length so that said second monopole radiating element is resonant within said second specified frequency band, wherein said second conductive trace is electrically coupled to said first conductive trace so as to receive signals through said first conductive trace when said printed monopole antenna is operated within said second specified frequency band.

20. A printed monopole antenna having a ground plane defined substantially perpendicular thereto and being operable within a first specified frequency band and a second specified frequency band, comprising;

(a) a first printed circuit board having a first side and a second side, said first printed circuit board lying in a plane substantially perpendicular to said ground plane;

(b) a second printed circuit board positioned adjacent to said first printed circuit board, said second printed circuit board having a first side and a second side;

(c) a first monopole radiating element comprising a first conductive trace formed on said first printed circuit board first side, said first conductive trace having a physical length from a feed end to an opposite end and a predetermined electrical length so that said first monopole radiating element is resonant within said first specified frequency band;

(d) a feed port including a signal feed portion and a ground portion, said signal feed portion being coupled only to said feed end of said first conductive trace; and

(e) a second monopole radiating element positioned adjacent to said first monopole radiating element and not connected to said feed port, said second monopole radiating element comprising a second conductive trace formed on said second printed circuit board first side having a physical length from a first end to a second end and a predetermined electrical length so that said second monopole radiating element is resonant within said second specified frequency band, wherein said second conductive trace is electrically coupled to said first conductive trace so as to receive signals through said first conductive trace when said printed monopole antenna is operated within said second specified frequency band.

21. The printed monopole antenna of claim 20, wherein said second printed circuit board second side is positioned adjacent said first printed circuit board first side.

22. The printed monopole antenna of claim 20, wherein said first and second printed circuit boards lie in planes oriented substantially parallel to each other.

23. The printed monopole antenna of claim 20, wherein said second printed circuit board is spaced a specified distance from said first printed circuit board to maintain a minimum voltage standing wave ratio at an antenna feed point.

24. The printed monopole antenna of claim 20, wherein said first and second printed circuit boards are made of a flexible dielectric material.

25. The printed monopole antenna of claim 20, wherein said first conductive trace, said second conductive trace, said first printed circuit board, and said second printed circuit board are overmolded.

26. A printed monopole antenna having a ground plane defined substantially perpendicular thereto and being operable within a first specified frequency band and a second specified frequency band, comprising:

(a) a substantially planar printed circuit board having a first side and a second side, said first printed circuit board lying in a plane substantially perpendicular to said ground plane;

(b) a feed port including a signal feed portion and a ground portion;

(c) a first monopole radiating element comprising a first conductive trace formed on said printed circuit board first side, said first conductive trace being coupled to said signal feed portion of said feed port and having an electrical length so as to be resonant within said first specified frequency band; and

(d) a second monopole radiating element comprising a second conductive trace formed on said printed circuit board first side adjacent said first conductive trace, said second conductive trace having an electrical length so as to be resonant within said second specified frequency band, wherein said second monopole radiating element is electrically coupled to said first monopole radiating element so as to receive signals through said first monopole radiating element when said printed monopole antenna is operated within said second specified frequency band.

27. The printed monopole antenna of claim 26, wherein said second monopole radiating element is not connected to ground.

28. A printed monopole antenna having a ground plane defined substantially perpendicular thereto and being operable within a first specified frequency band and a second specified frequency band, comprising:

(a) a substantially planar printed circuit board having a first side and a second side, said first printed circuit board lying in a plane substantially perpendicular to said ground plane;

(b) a feed port including a signal feed portion and a ground portion;

(c) a first monopole radiating element comprising a first conductive trace formed on said printed circuit board first side, said first conductive trace being coupled to said signal feed portion of said feed port and having an electrical length so as to be resonant within said first specified frequency band; and

(d) a second monopole radiating element comprising a second conductive trace formed on said printed circuit board second side adjacent said first conductive trace, said second conductive trace having an electrical length so as to be resonant within said second specified frequency band, wherein said second monopole radiating element is electrically coupled to said first monopole radiating element so as to receive signals through said first monopole radiating element when said printed monopole antenna is operated within said second specified frequency band.

29. A printed monopole antenna having a ground plane defined substantially perpendicular thereto and being operable within a first specified frequency band and a second specified frequency band, comprising:

(a) a first substantially planar printed circuit board having a first side and a second side, said first printed circuit board lying in a plane substantially perpendicular to said ground plane;

(b) a feed port including a signal feed portion and a ground portion;

(c) a first monopole radiating element comprising a first conductive trace formed on said first printed circuit board first side, said first conductive trace being coupled to said signal feed portion of said feed port and having an electrical length so as to be resonant within said first specified frequency band;

(d) a second substantially planar printed circuit board having a first side and a second side, wherein said second printed circuit board second side is positioned adjacent to and substantially parallel with said first printed circuit board first side; and

(e) a second monopole radiating element comprising a second conductive trace formed on said second printed circuit board first side, said second conductive trace having an electrical length so as to be resonant within said second specified frequency band, wherein said second conductive trace is electrically coupled to said first conductive trace so as to receive signals through said first conductive trace when said printed monopole antenna is operated within said second specified frequency band.

30. A printed monopole antenna having a ground plane defined substantially perpendicular thereto and being operable within a plurality of specified frequency bands, comprising:

(a) a substantially planar printed circuit board having a first side and a second side, said first printed circuit board lying in a plane substantially perpendicular to said ground plane;

(b) a feed port including a signal feed portion and a ground portion; and

(c) a plurality of monopole radiating elements, each said monopole radiating element comprising a conductive trace formed on one of said printed circuit board sides adjacent each other and having a specified electrical length so as to be resonant within a specified frequency band, wherein only one of said conductive traces is coupled to said signal feed portion of said feed port and the other conductive traces are electrically coupled thereto so as to receive signals through said first conductive trace when said printed monopole antenna is operated within said specified frequency band of resonance therefore.

31. The printed monopole antenna of claim 30, wherein said conductive traces are oriented substantially parallel to each other.

32. The printed monopole antenna of claim 30, wherein said conductive traces have substantially equivalent physical lengths.

33. The printed monopole antenna of claim 30, wherein at least one of said conductive traces has a physical length different than said remaining conductive traces.

34. The printed monopole antenna of claim 30, wherein no direct electrical connection exists between said plurality of monopole radiating elements.

35. The printed monopole antenna of claim 30, wherein said second monopole radiating element is not connected to ground.

36. A printed monopole antenna having a ground plane defined substantially perpendicular thereto and being operable within a plurality of specified frequency bands comprising:

(a) a substantially planar first printed circuit board having a first side and a second side, said first printed circuit board lying in a plane substantially perpendicular to said ground plane;

(b) a substantially planar second printed circuit board having a first side and a second side, said second side of said second printed circuit board being positioned adjacent to and substantially parallel with said first side of said first printed circuit board;

(c) a feed port including a signal feed portion and a ground portion;

(d) at least one monopole radiating element associated with said first printed circuit board, each of said monopole radiating elements comprising a conductive trace formed on said first printed circuit board first side and having a specified electrical length so as to be resonant within one of said specified frequency bands, wherein one of said conductive traces is coupled to said signal feed portion of said feed port and any other conductive traces are electrically coupled thereto so as to receive signals through said fed conductive trace conductive trace having an electrical length so as to be resonant within a; and

(e) at least one monopole radiating element associated with said second printed circuit board, each of said monopole radiating elements comprising a conductive trace formed on said second circuit board first side and having a specified electrical length so as to be resonant within one of said specified frequency bands, wherein each conductive trace is electrically coupled to said fed conductive trace on said first printed circuit board so as to receive signals through said fed conductive trace.

37. The printed monopole antenna of claim 36, wherein said conductive traces are oriented substantially parallel to each other.

38. The printed monopole antenna of claim 36, wherein said conductive traces have substantially equivalent physical lengths.

39. The printed monopole antenna of claim 36, wherein at least one of said conductive traces has a physical length different than said remaining conductive traces.

40. The printed monopole antenna of claim 36, wherein no direct electrical connection exists between said plurality of monopole radiating elements.

41. The printed monopole antenna of claim 36, wherein said first and second printed circuit boards lie in planes oriented substantially parallel to each other.

42. The printed monopole antenna of claim 36, wherein said second printed circuit board is spaced a specified distance from said first printed circuit board to maintain a minimum voltage standing wave ratio.