Compact dual band circular PIFA

• US 20030231134A1
• Filed: 01/14/2003
• Published: 12/18/2003
• Est. Priority Date: 06/18/2002
• Status: Active Grant

• Current Assignee: Centurion Industries Incorporated (Laird Limited)
• Original Assignee: Centurion Industries Incorporated (Laird Limited)
• Inventors: Hebron, Theodore S., Kadambi, Govind R., Yarasi, Sripathi
• Granted Patent: US 6,710,748 B2
• Time in Patent Office: Days
• US Class Current: 343/700.0MS
• CPC Class Codes: H01Q 1/241 used in mobile communications, e.g. GSM H01Q1/247, H01Q1/248 take precedence
• 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

The present invention relates to a non-rectangular shaped PIFA capable of dual ISM band operation using a single power feed. The dual frequency operation of the PIFA is accomplished by using a slot in-the radiating element to quasi partition the radiating element. The dual band performance of the PIFA is realized through the integration of either the microstrip or the Co Planar Waveguide (CPW) feed line to the antenna structure.

Claims

1. A planar inverted F antenna comprising.

a non-rectangular radiating element comprising an internal side, an external side, and a peripheral edge;

a dielectric carriage comprising a radiating side, a ground side, and at least one sidewall;

the non-rectangular radiating element resides on the dielectric carriage such that the internal side of the radiating element resides closer to the radiating side of the dielectric carriage;

a ground plane comprising a feed side and a carriage side;

the dielectric carriage resides on the ground plane such that the carriage side of the ground plane resides closer to the ground side of the dielectric carriage;

a slot;

the slot resides in the internal side of the radiating element;

a feed pin;

the feed pin attached to the internal side of the radiating element;

a dielectric carriage feed pin via hole;

a ground plane feed pin via hole;

the feed pin extends from the internal side of the radiating element through the dielectric carriage feed pin via hole and the ground plane feed pin via hole and is adapted to attach to a microstrip feed line;

a conducting post;

the conducting post attached to the internal side of the radiating element;

a dielectric carriage conducting post via hole;

the conducting post extends from the internal side of the radiating element to the carriage side of the ground plane through the dielectric carriage conducting post via hole and is attached to the dielectric side of the ground plane;

a matching stub;

the matching stub attached to the peripheral edge of the radiating element; and

the matching stub has a downward extension from the peripheral edge of the radiating element and the matching stub not touching the ground plane;

the matching stub is in flush with the sidewall of the dielectric carriage; and

the matching stub has a downward extension from the peripheral edge of the radiating element, such that the matching stub resides off the ground plane and is flush with the sidewall of the dielectric carriage.

7. The antenna of claim 1, wherein the non-rectangular radiating element has a shape comprising at least one of circular, semi-circular, elliptical, and semi-elliptical.

8. The antenna of claim 1, wherein the non-rectangular radiating element has a non-geometric, irregular shape.

9. The antenna of claim 1, wherein the dielectric carriage comprises at least one of HDPE (High Density Poly Ethylene), ABS (Acrolonitrite Butadiene Styrene), and Polycarbonate.

10. The antenna of claim 9, wherein the dielectric carriage has a dielectric constant of about 2.5 to about 3.5.

11. The antenna of claim 1, wherein the slot comprises at least one of a horse-shoe shape, a bracket shape, a U-shape, a L-shape, a T-shape, and an inclined shape.

12. The antenna of claim 11, wherein the slot partitions the radiating element to allow for dual ISM band operation.

13. The antenna of claim 11, wherein the slot is the horse-shoe shape slot and the horse-shoe shape arcs from a first point in line with where the feed pin is attached to the radiating element to a second point in line with where the conducting post is attached to the radiating element.

14. The antenna of claim 13, where the arc ranges from about 180 degrees to about 270 degrees.

15. The antenna of claim 1, wherein an electrical size of the antenna is about a quarter wave-length at the mid frequency of the lower resonant band.

2. The antenna of 1, further comprising:

a microstrip feed;

a substrate;

the microstrip feed comprises a ground plane side and a substrate side;

the microstrip feed line extends over the substrate to the ground plane such that the substrate side of the microstrip feed resides closer to the substrate and the ground plane side resides closer to the ground plane; and

the microstrip feed line is attached to the feed pin at a point aligned with the ground plane feed pin via hole.

3. The antenna of claim 3, wherein the substrate comprises a printed circuit board having a metallic region and a non-metallic region.

4. The antenna of claim 3, wherein the radiating element is positioned such that parts of the radiating element reside over both the metallic region and the non-metallic region of printed circuit board, where the ground plane of the antenna is connected to the metallic region of the printed circuit board at selective points.

5. The antenna of claim 3, wherein the radiating element is positioned such that a greater part of the radiating element resides over the non-metallic region of printed circuit board.

6. The antenna of claim 3, wherein the radiating element is positioned such that a greater part of the radiating element resides over the metallic region of printed circuit board.

16. A planar inverted F antenna comprising:

a non-rectangular radiating element comprising an internal side, an external side and a peripheral edge;

a dielectric carriage comprising a radiating side, a ground side, and at least one sidewall;

the non-rectangular radiating element resides on the dielectric carriage such that the internal side of the radiating element resides closer to the radiating side of the dielectric carriage;

a ground plane comprising a feed side and a carriage side;

the dielectric carriage resides on the ground plane such that the carriage side of the ground plane resides closer to the ground side of the dielectric carriage;

a horse-shoe shaped slot;

a feed pin;

the feed pin attached to the internal side of the radiating element;

a dielectric carriage feed pin via hole;

a ground plane feed pin via hole;

the feed pin extends from the internal side of the radiating element through the dielectric carriage feed pin via hole and the ground plane feed pin via hole and is adapted to attach to a microstrip feed line;

a conducting post;

the conducting post attached to the internal side of the radiating element;

a dielectric carriage conducting post via hole;

the conducting post extends from the internal side of the radiating element to the carriage side of the ground plane through the dielectric carriage conducting post via hole and is attached to the dielectric side of the ground plane;

the first point lies to the left of the feed pin and the second point is located to the right of the conducting post;

the horse-shoe shaped slot extends in an arc from a first point in line with the feed pin to a second point in line with the conducting post;

a matching stub;

the matching stub attached to the peripheral edge of the radiating element; and

the matching stub has a downward extension from the peripheral edge of the radiating element, such that the matching stub not touching the ground plane and is in flush with the sidewall of the dielectric carriage.1

17. The antenna of claim 16, further comprising:

a microstrip feed;

a substrate;

the microstrip feed comprises a ground plane side and a substrate side;

the microstrip feed line extends over the substrate to the ground plane such that the substrate side of the microstrip feed resides closer to the substrate and the ground plane side resides closer to the ground plane; and

the microstrip feed line is attached to the feed pin at a point aligned with the ground plane feed pin via a hole.

18. The antenna of claim 17, wherein the substrate comprises a printed circuit board having a metallic region and a non-metallic region, where the ground plane of the antenna is connected to the metallic region of the printed circuit board at selective points.

19. The antenna of claim 18, wherein the radiating element resides in proximity to an interface between the metallic region and the non-metallic region of printed circuit board.

20. The antenna of claim 17, wherein the slot partitions the radiating element to allow for dual ISM band operation.

21. The antenna of claim 17, wherein the radiating element has an unbroken circumference.

22. The antenna of claim 17, wherein the horse-shoe shaped slot forms an arc from a first point in line with where the feed pin is attached to the radiating element to a second point in line with where the conducting post is attached to the radiating element.

23. The antenna of claim 17, wherein the feed pin, the conducting post, and matching stub are attached using solder.

24. The antenna of claim 17, wherein an electrical size of the antenna is about a quarter wave-length at the mid frequency of the lower resonant band.

25. The antenna of claim 17, wherein the non-rectangular radiating element has a shape comprising at least one of circular, semi-circular, elliptical, and semi-elliptical.

26. The antenna of claim 17, wherein the non-rectangular radiating element has a non-geometric, irregular shape.

27. A planar inverted F antenna comprising:

a non-rectangular radiating element comprising an internal side and an external side and a peripheral edge;

a dielectric carriage comprising a radiating side, a ground side, and at least one sidewall;

the non-rectangular radiating element resides on the dielectric carriage such that the internal side of the radiating element resides closer to the radiating side of the dielectric carriage;

a ground plane comprising a feed side and a carriage side;

the dielectric carriage resides on the ground plane such that the carriage side of the ground plane resides closer to the ground side of the dielectric carriage;

a “

U”

shaped slot;

a feed pin;

the feed pin attached to the internal side of the radiating element;

a dielectric carriage feed pin via hole;

a ground plane feed pin via hole;

the feed pin extends from the internal side of the radiating element through the dielectric carriage feed pin via hole and the ground plane feed pin via hole and is adapted to attach to a microstrip feed line;

a conducting post;

the conducting post attached to the internal side of the radiating element;

a dielectric carriage conducting post via hole;

the conducting post extends from the internal side of the radiating element to the carriage side of the ground plane through the dielectric carriage conducting post via hole and is attached to the dielectric side of the ground plane;

a matching stub;

the matching stub attached to the peripheral edge of the radiating element; and

the matching stub has a downward extension from the peripheral edge of the radiating element such that the matching stub resides off the ground plan and is in flush with the sidewall of the dielectric carriage.

28. The antenna of claim 27, further comprising:

a microstrip feed;

a substrate;

the microstrip feed comprises a ground plane side and a substrate side;

the microstrip feed line extends over the substrate to the ground plane such that the substrate side of the microstrip feed resides closer to the substrate and the ground plane side resides closer to the ground plane; and

the microstrip feed line is attached to the feed pin at a point aligned with the ground plane feed pin via a hole.

29. The antenna of claim 27, wherein the substrate comprises a printed circuit board having a metallic region and a non-metallic region. The ground plan of the antenna is connected to the metallic region of the printed circuit board at selective points.

30. The antenna of claim 29, wherein the radiating element resides in proximity to an interface between the metallic region and the non-metallic region of the printed circuit board.

31. The antenna of claim 27, wherein the slot partitions the radiating element to allow for dual ISM band operation.

32. The antenna of claim 27, wherein the radiating element has an unbroken circumference.

33. The antenna of claim 27, wherein

the U-shaped slot has first and second vertical segments and a horizontal segment;

the first and second vertical segments of the U-shaped slot are parallel to each other;

the first and second vertical segments of the U-shaped slots are on either side of the horizontal segment of the U-shaped slot;

the first vertical segment of the U-shaped slot on the internal side of the radiating element is generally perpendicular to the line containing the feed pin and conducting post;

the horizontal segment of the U-shaped slot extends from said first vertical segment of the U-shaped slot generally parallel to the line containing the feed pin and the conducting post;

the second vertical segment of the U-shaped slot extends from said horizontal segment of the U-shaped slot generally perpendicular to the line containing the feed pin and the conducting post;

the axis of the horizontal segment of the U-shaped slot is parallel to the line containing the feed pin and the conducting post;

the axes of the first and second vertical segments of the U-shaped slot are perpendicular to the axis of the horizontal segment of the U-shaped slot;

the U-shaped slot resides in the internal side of the radiating element such that the horizontal segment of the U-shaped slot is above the line containing the feed pin and the conducting post; and

the U-shaped slot resides in the internal side of the radiating element such that the first and second vertical segments are outside the line connecting the feed pin and the conducting post.

34. The antenna of claim 27, wherein an electrical size of the antenna is about a quarter wave-length at the mid frequency of the lower resonant band.

35. The antenna of claim 27, wherein the non-rectangular radiating element has a shape comprising at least one of circular, semi-circular, elliptical, and semi-elliptical.

36. The antenna of claim 27, wherein the non-rectangular radiating element has a non-geometric, irregular shape.

37. A planar inverted F antenna, comprising:

a non-rectangular radiating element comprising an internal side, an external side, and a peripheral edge;

a dielectric carriage comprising a radiating side, a ground side, and at least one sidewall; and

the non-rectangular radiating element resides on the dielectric carriage such that the internal side of the radiating element resides closer to the radiating side of the dielectric carriage;

a ground plane comprising a feed side, a carriage side, and a ground plane edge;

the dielectric carriage resides on the ground plane such that the carriage side of the ground plane resides closer to the ground side of the dielectric carriage;

a slot;

the slot resides in the internal side of the radiating element;

a feed strip;

the feed pin attached to the peripheral edge of the radiating element;

the feed pin extends from the peripheral edge along the at least one sidewall towards the ground plane edge and is adapted to be attached to a Co Planar Waveguide;

a conducting post;

the conducting post attached to the peripheral edge;

the conducting post extends from the peripheral edge along the at least one sidewall and is attached to the ground plane edge;

a matching stub;

the matching stub attached to the peripheral edge;

the matching stub extends from the peripheral edge along the at least one sidewall; and

the matching stub is in flush with the sidewall of the dielectric carriage.

41. The antenna of claim 37, wherein the slot partitions the radiating element to allow for dual ISM band operation.

42. The antenna of claim 37, wherein the slot forms a gap in a circumference of the radiating element.

43. The antenna of claim 37, wherein the slot is “

L”

shaped, the L-shaped slot has a vertical segment and a horizontal segment,

the horizontal segment of the L-shaped slot has an open end or gap located on the peripheral edge of the radiating element;

the vertical segment of the L-shaped slot has a closed end located on the internal side of the radiating element; and

the vertical segment of the L-shaped slot extends from said horizontal segment of the L-shaped slot such that the axes of vertical and horizontal segments of the L-shaped slot are nearly perpendicular to each other.

44. The antenna of claim 37, wherein an electrical size of the antenna is smaller than a quarter wave length at the mid frequency of the lower resonant band.

45. The antenna of claim 37, wherein the non-rectangular radiating element has a shape comprising at least one of circular, semi-circular, elliptical, and semi-elliptical.

46. The antenna of claim 37, wherein the non-rectangular radiating element has a non-geometric, irregular shape.

38. The antenna of 37, further comprising:

a CPW feed;

a substrate;

the CPW feed comprises a ground plane side and a substrate side;

the CPW feed line extends over the substrate to the ground plane such that the substrate side of the CPW feed resides closer to the substrate; and

the CPW feed line is attached to the feed pin at the ground plane edge.

39. The antenna of claim 38, wherein the substrate comprises a printed circuit board having a metallic region and a non-metallic region, where the ground plane of the antenna is connected to the metallic region of the printed circuit board at selective points.

40. The antenna of claim 38, wherein the radiating element resides in proximity to an interface between the metallic region and the non-metallic region of printed circuit board.

47. A planar inverted F antenna comprising:

means for radiating in a frequency band;

a ground plane;

means for separating the means for radiating and the ground plane;

means for partitioning the means for radiating in a frequency band so that the means for radiating operates at a plurality of frequencies;

means for supplying power to the means for radiating;

means for supplying a short between the ground plane and the means for radiating; and

means for matching the impedance of the means for radiating;