PLANAR INVERTED-F-ANTENNA (PIFA) HAVING A SLOTTED RADIATING ELEMENT PROVIDING GLOBAL CELLULAR AND GPS-BLUETOOTH FREQUENCY RESPONSE

• US 20040085244A1
• Filed: 11/06/2002
• Published: 05/06/2004
• Est. Priority Date: 11/06/2002
• Status: Active Grant

• Current Assignee: Laird Technologies Incorporated (DuPont de Nemours, Inc.)
• Original Assignee: Centurion Industries Incorporated (Laird Limited)
• Inventors: Meza, Antonio Barron, Kadambi, Govind Rangaswamy, Yarasi, Sripathi, Hebron, Theodore Samuel
• Granted Patent: US 6,741,214 B1
• Time in Patent Office: Days
• US Class Current: 343/700MS
• CPC Class Codes: H01Q 5/357 using a single feed point
• CPC Class Codes: H01Q 5/371 Branching current paths
• CPC Class Codes: H01Q 9/0421 with a shorting wall or a shorting pin at one end of the element H01Q9/0414 takes precedence
• CPC Class Codes: H01Q 9/0442 with particular tuning means

Abstract

Single feed planar inverted-F antennas (PIFAs) are provided for three, four or five frequency bands of resonance in both cellular and non-cellular frequency bands. The PIFAs include a dielectric carriage having a metal radiating element located on a top surface thereof and sidewalls having a metal ground plane element located at the bottom of the sidewalls. The non-radiating edge of the radiating elements include a downward extending shorting strip that is connected to the ground plane element and a downward extending feed strip that is spaced above the ground plane element and is connected to a feed cable. The radiating element includes downward extending matching and loading plates whose free ends are spaced above the ground plane element, which provide impedance matching and reactive loading to the radiating elements. Configurations of slots (open and closed) within the radiating elements selectively provide multiple frequency resonance to the radiating elements in both cellular and non-cellular frequency bands.

Claims

1. A method of providing a PIFA having a single feed and having more than two frequency bands of resonance, comprising the steps of:

providing a dielectric carriage having a top surface and sidewalls that extend generally perpendicular from said top surface, a bottom of said sidewalls defining a bottom surface that is generally parallel to said top surface;

providing a metal ground plane element on said bottom surface;

providing a metal radiating element on said top surface;

said radiating element having a radiating edge and a non-radiating edge;

providing a metal shorting strip on said non-radiating edge of said radiating element that extends downward from said radiating element and is electrically connected to said ground plane element;

providing a metal feed strip on said non-radiating edge of said radiating element that extends downward from said radiating element and has a free end that is spaced above said ground plane element;

providing a feed cable;

connecting said feed cable to said free end of said feed strip;

providing a slot configuration in said metal radiating element;

providing downward extending metal plates on said metal radiating element;

said downward extending metal plates having free ends that are spaced above said ground plane element; and

configuring said slot configuration and said downward extending metal plates to provide said more than two frequency bands of resonance.

2. The method of claim 1 wherein said downward extending metal plates are closely associated with said sidewalls of said dielectric carriage.

3. The method of claim 2 wherein said more than two frequency bands are selected from the group three, four or five frequency bands.

4. The method of claim 1 wherein said metal radiating element is formed by the steps of:

providing a generally flat sheet of metal;

punching/cutting said generally flat sheet of metal to form said slot configuration and outward extending metal plates in said generally flat metal sheet; and

bending said outward extending metal plates downward to form said downward extending metal plates on said metal radiating element.

5. The method of claim 1 wherein said more than two frequency bands comprise four frequency bands, and including the step of:

providing said slot configuration as a generally C-shaped slot that is interrupted by a conductive metal stub that is located adjacent to said radiating edge of said radiating element;

said generally C-shaped slot forming said radiating element into an inner radiating element and an outer radiating element that is electrically connected to said inner radiating element by said conductive metal stub; and

providing a slot on said non-radiating edge of said radiating element in a location that is between said shorting strip and said feed strip.

6. The method of claim 5 wherein said generally C-shaped slot includes:

a first slot portion that extends from one side of said conductive metal stub generally parallel to said non-radiating edge;

a second slot portion that extends from said first slot portion generally perpendicular to said non-radiating edge;

a third slot portion that extends from said second slot portion generally parallel to said non-radiating edge;

a fourth slot portion that extends from said third slot portion generally perpendicular to said non-radiating edge; and

a fifth slot portion that extends from said fourth slot portion generally parallel to said non-radiating edge to an opposite side of said conductive metal stub.

7. The method of claim 6 wherein said slot connects to said third slot portion of said generally C-shaped slot.

8. The method of claim 7 wherein said downward extending metal plates are closely associated with said sidewalls.

9. The method of claim 8 wherein said metal radiating element is formed by the steps of:

providing a generally flat sheet of metal;

punching/cutting said generally flat sheet of metal to form said generally C-shaped slot, said conductive metal stub, said slot and said outward extending metal plates in said generally flat metal sheet; and

bending said outward extending metal plates downward to form said downward extending metal plates on said metal radiating element.

10. The method of claim 1 wherein said more than two frequency bands comprise four frequency bands, and including the step of:

providing said slot configuration as a first generally C-shaped slot that is interrupted by a first conductive metal stub located adjacent to said non-radiating edge, and a second generally C-shaped slot that surrounds said first generally C-shaped slot and is interrupted by a second conductive metal stub located adjacent to said non-radiating edge;

said first generally C-shaped slot forming a inner radiating element;

said second generally C-shaped slot forming a middle radiating element that is connected to said inner radiating element by said first conductive metal stub; and

said second generally C-shaped slot forming an outer radiating element that is electrically connected to said middle radiating element by said second conductive metal stub.

11. The method of claim 10 wherein said metal radiating element is formed by the steps of:

providing a generally flat sheet of metal;

punching/cutting said generally flat sheet of metal to form said first and second generally C-shaped slots, said first and second conductive metal stubs and said outward extending metal plates in said generally flat metal sheet; and

bending said outward extending metal plates downward to form said downward extending metal plates on said metal radiating element.

12. The method of claim 10 wherein:

said first generally C-shaped slot includes a first slot portion extending from one side of said first conductive stub generally parallel to said non-radiating edge, a second slot portion extending from said first slot portion generally perpendicular to said non-radiating edge, a third slot portion extending from said second slot portion generally parallel to said non-radiating edge, a fourth slot portion extending from said third slot portion generally perpendicular to said non-radiating edge, and a fifth slot portion extending from said fourth slot portion generally parallel to said non-radiating edge to an opposite side of said first conductive stub; and

said second generally C-shaped slot includes a first slot portion extending from one side of said second conductive stub generally parallel to said non-radiating edge, a second slot portion extending from said first slot portion generally perpendicular to said non-radiating edge, a third slot portion extending from said second slot portion generally parallel to said non-radiating edge, a fourth slot portion extending from said third slot portion generally perpendicular to said non-radiating edge, and a fifth slot portion extending from said fourth slot portion generally parallel to said non-radiating edge to an opposite side of said second conductive stub

13. The method of claim 12 wherein said downward extending metal plates are closely associated with said sidewalls of said dielectric carriage.

14. The method of claim 1 wherein said more than two frequency bands comprise five frequency bands, and including the step of:

providing said slot configuration as a first generally L-shaped slot having an end that is located on said non-radiating edge intermediate said shorting strip and said feed strip, a second generally L-shaped slot having an end located on said non-radiating edge, and a third slot that is located intermediate said first and second generally L-shaped slots having an end that is located on said non-radiating edge intermediate said ends of said first and second generally L-shaped slots.

15. The method of claim 14 wherein said metal radiating element is formed by the steps of:

providing a generally flat sheet of metal;

punching/cutting said generally flat sheet of metal to form said first and second generally L-shaped slots, said third slot and said outward extending metal plates in said generally flat metal sheet; and

bending said outward extending metal plates downward to form said downward extending metal plates on said metal radiating element.

16. The method of claim 14 wherein:

said first and second generally L-shaped slots include a first slot portion extending generally perpendicular from said non-radiating edge, and a second slot portion extending from said first slot portion generally parallel to said non-radiating edge; and

said third slot includes a first slot portion extending generally perpendicular from said non-radiating edge, a second slot portion extending from said first slot portion generally parallel to said non-radiating edge, a third slot portion extending from said second slot portion generally perpendicular to said non-radiating edge, and a fourth slot portion extending from said third slot portion generally parallel to said non-radiating edge.

17. The method of claim 16 wherein said downward extending metal plates are closely associated with said sidewalls of said dielectric carriage.

18. The method of claim 1 wherein said more than two frequency bands comprise three frequency bands, and including the step of:

providing said slot configuration as a generally C-shaped slot that is interrupted by a conductive metal stub that is located adjacent to said non-radiating edge of said radiating element;

said generally C-shaped slot forming said radiating element into an inner radiating element and an outer radiating element that is electrically connected to said inner radiating element by said conductive metal stub;

providing a downward extending plate on said radiating edge of said radiating element; and

providing a generally L-shaped slot in said downward extending plate;

said generally L-shaped slot having an open end located adjacent to said ground plane element.

19. The method of claim 18 wherein;

said generally C-shaped slot includes a first slot portion extending from one side of said conductive stub generally parallel to said non-radiating edge, a second slot portion extending from said first slot portion generally perpendicular to said non-radiating edge, a third slot portion extending from said second slot portion generally parallel to said non-radiating edge, a fourth slot portion extending from said third slot portion generally perpendicular to said non-radiating edge, and a fifth slot portion extending from said fourth slot portion generally parallel to said non-radiating edge to an opposite side of said conductive stub; and

said L-shaped slot includes a first slot portion that extends from said end generally perpendicular to said radiating edge, and a second slot portion extending from said first slot portion generally parallel to said radiating edge.

20. The method of claim 19 wherein said downward extending metal plates are closely associated with said sidewalls of said dielectric carriage.

21. The method of claim 18 wherein said metal radiating element is formed by the steps of:

providing a generally flat sheet of metal;

punching/cutting said generally flat sheet of metal to form said generally C-shaped slot, said conductive metal stub and said generally L-shaped slot in said generally flat metal sheet; and

bending said outward extending metal plates downward to form said downward extending metal plates on said metal radiating element.

22. A PIFA having a single feed and having more than two frequency bands of resonance, comprising:

a dielectric carriage having a top surface and sidewalls that extend downward from said top surface, a bottom of said sidewalls defining a bottom surface;

a metal ground plane element generally abutting said bottom surface;

a metal radiating element generally abutting said top surface;

said radiating element having a radiating edge and a non-radiating edge;

a metal shorting strip extending downward from said non-radiating edge and electrically connected to said ground plane element;

a metal feed strip extending downward from said non-radiating edge and having a free end spaced from said ground plane element;

a feed cable connected to said free end of said feed strip;

metal plates extending downward from said radiating element in a generally abutting relationship with said sidewalls; and

said metal plates having free ends that are spaced from said ground plane element.

23. The PIFA of claim 22 wherein said more than two frequency bands are selected from the group three, four or five frequency bands.

24. A PIFA having a single feed and four frequency bands of resonance, comprising:

a dielectric carriage having a top surface and sidewalls that extend from said top surface;

said sidewalls having bottom surfaces that are spaced from and extends generally parallel to said top surface and that define a bottom surface;

a metal ground plane element generally abutting said bottom surface carriage;

a metal radiating element generally abutting said top surface;

said radiating element having a radiating edge and a non-radiating edge;

a metal shorting strip extending downward from said non-radiating edge and electrically connected to said ground plane element;

a metal feed strip extending downward from said non-radiating edge and having a free end that is spaced from said ground plane element;

a feed cable connected to said free end of said feed strip;

metal tuning plates extending downward from said radiating element in a generally abutting relationship with said sidewalls;

said metal tuning plates having free ends that are spaced from said ground plane element;

a generally C-shaped slot formed in said radiating element and interrupted by a conductive metal stub that is located adjacent to said radiating edge of said radiating element;

said generally C-shaped slot forming said radiating element into an inner radiating element and an outer radiating element that is electrically connected to said inner radiating element by said conductive metal stub; and

an open slot on said non-radiating edge of said radiating element in a location that is between said shorting strip and said feed strip.

25. The PIFA of claim 24 wherein said generally C-shaped slot includes:

a first slot portion that extends from one side of said conductive metal stub generally parallel to said radiating edge;

a second slot portion that extends from said first slot portion generally perpendicular to said radiating edge;

a third slot portion that extends from said second slot portion generally parallel to said radiating edge;

a fourth slot portion that extends from said third slot portion generally perpendicular to said radiating edge; and

a fifth slot portion that extends from said fourth slot portion generally parallel to said radiating edge to an opposite side of said conductive metal stub.

26. The PIFA of claim 25 wherein said open slot connects to said third slot portion of said generally C-shaped slot.

27. A PIFA having a single feed and four frequency bands of resonance, comprising:

a dielectric carriage having a top surface and a bottom surface that is defined by sidewalls that extend between said top surface and said bottom surface, said bottom surface being spaced from and extending generally parallel to said top surface;

a metal ground plane element generally abutting said bottom surface;

a metal radiating element generally abutting said top surface;

said radiating element having a radiating edge and a non-radiating edge;

a metal shorting strip extending downward from said non-radiating edge and electrically connected to said ground plane element;

a metal feed strip extending downward from said non-radiating edge and having a free end that is spaced from said ground plane element;

a feed cable connected to said free end of said feed strip;

metal tuning plates extending downward from said radiating element in a generally abutting relationship with said sidewalls;

said metal tuning plates having free ends that are spaced from said ground plane element;

a first generally C-shaped slot formed in said radiating element and interrupted by a first conductive metal stub that is located adjacent to said non-radiating edge;

a second generally C-shaped slot formed in said radiating element so as to generally surround said first generally C-shaped slot and interrupted by a second conductive metal stub that is located adjacent to said non-radiating edge;

said first generally C-shaped slot forming an inner radiating element;

said second generally C-shaped slot forming a middle radiating element that is connected to said inner radiating element by said first conductive metal stub; and

said second generally C-shaped slot forming an outer radiating element that is electrically connected to said middle radiating element by said second conductive metal stub.

28. The PIFA of claim 27 wherein:

said first generally C-shaped slot includes a first slot portion extending from one side of said first conductive stub generally parallel to said non-radiating edge, a second slot portion extending from said first slot portion generally perpendicular to said non-radiating edge, a third slot portion extending from said second slot portion generally parallel to said non-radiating edge, a fourth slot portion extending from said third slot portion generally perpendicular to said non-radiating edge, and a fifth slot portion extending from said fourth slot portion generally parallel to said non-radiating edge to an opposite side of said first conductive stub; and

said second generally C-shaped slot includes a first slot portion extending from one side of said second conductive stub generally parallel to said non-radiating edge, a second slot portion extending from said first slot portion generally perpendicular to said non-radiating edge, a third slot portion extending from said second slot portion generally parallel to said non-radiating edge, a fourth slot portion extending from said third slot portion generally perpendicular to said non-radiating edge, and a fifth slot portion extending from said fourth slot portion generally parallel to said non-radiating edge to an opposite side of said second conductive stub.

29. The PIFAS of claim 28 including:

a metal plate extending downward from said radiating edge in a generally abutting relationship with a sidewall of said dielectric carriage;

said metal plate having a free end spaced from said ground plane element; and

a generally L-shaped slot formed in said metal plate;

said generally L-shaped slot having an open end located adjacent to said ground plane element, and having a slot segment that extends generally parallel to said radiating edge.

30. PIFA having a single feed and five frequency bands of resonance, comprising:

a dielectric carriage having a top surface, having a bottom surface that is spaced from and extends generally parallel to said top surface, and having sidewalls that extend between said top and bottom surfaces, said bottom surface being defined by bottom ends of said sidewalls;

a metal ground plane element generally abutting said bottom surface;

a metal radiating element generally abutting said top surface;

said radiating element having a radiating edge and a non-radiating edge;

a metal shorting strip extending downward from said non-radiating edge and electrically connected to said ground plane element;

a metal feed strip extending downward from said non-radiating edge and having a free end that is spaced from said ground plane element;

a feed cable connected to said free end of said feed strip;

metal plates extending downward from said radiating element and having feed ends that are spaced from said ground plane element;

a first generally L-shaped slot on said radiating element having an open end located on said non-radiating edge intermediate said shorting strip and said feed strip;

a second generally L-shaped slot on said radiating element having an open end located on said non-radiating edge; and

a third slot on said radiating element located intermediate said first and second generally L-shaped slots having an open end located on said non-radiating edge intermediate said open ends of said first and second generally L-shaped slots.

31. The PIFA of claim 30 wherein:

said first and second generally L-shaped slots include a first slot portion extending generally perpendicular from said non-radiating edge, and a second slot portion extending from said first slot portion generally parallel to said non-radiating edge; and

said third slot includes a first slot portion extending generally perpendicular from said non-radiating edge, a second slot portion extending from said first slot portion generally parallel to said non-radiating edge, a third slot portion extending from said second slot portion generally perpendicular to said non-radiating edge, and a fourth slot portion extending from said third slot portion generally parallel to said non-radiating edge.

32. The method of claim 31 wherein said downward extending metal plates are closely associated with said sidewalls of said dielectric carriage.

33. PIFA having a single feed and three frequency bands of resonance, comprising:

a dielectric carriage having a top surface and a bottom surface that is defined by sidewalls that extend form said top surface, said bottom surface being spaced from and generally parallel to said top surface;

a metal ground plane element generally abutting said bottom surface;

a metal radiating element generally abutting said top surface;

said radiating element having a radiating edge and a non-radiating edge;

a metal shorting strip extending downward from said non-radiating edge and electrically connected to said ground plane element;

a metal feed strip extending downward from said non-radiating edge and having a free end that is spaced from said ground plane element;

a feed cable connected to said free end of said feed strip;

metal plates extending downward from said radiating element in a generally abutting relationship with said sidewalls and having free ends that are spaced from said ground plane element;

a generally C-shaped slot formed in said radiating element;

a conductive metal stub located adjacent to said non-radiating edge of said radiating element and interrupting said generally C-shaped slot;

said generally C-shaped slot partitioning said radiating element into an inner radiating element and an outer radiating element that is electrically connected to said inner radiating element by said conductive metal stub;

a downward extending plate on said radiating edge of said radiating element; and

a generally L-shaped slot in said downward extending plate;

said generally L-shaped slot having an open end located adjacent to said ground plane element.

34. The PIFA of claim 33 wherein;

said generally C-shaped slot includes a first slot portion extending from one side of said conductive stub generally parallel to said non-radiating edge, a second slot portion extending from said first slot portion generally perpendicular to said non-radiating edge, a third slot portion extending from said second slot portion generally parallel to said non-radiating edge, a fourth slot portion extending from said third slot portion generally perpendicular to said non-radiating edge, and a fifth slot portion extending from said fourth slot portion generally parallel to said non-radiating edge to an opposite side of said conductive stub; and

said L-shaped slot includes a first slot portion that extends from said open end generally perpendicular to said radiating edge, and a second slot portion extending from said first slot portion generally parallel to said radiating edge.