Low-cost, steerable, phased array antenna

• US 20050134403A1
• Filed: 12/17/2003
• Published: 06/23/2005
• Est. Priority Date: 12/17/2003
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Kajiya, James T.
• Granted Patent: US 7,034,748 B2
• Time in Patent Office: Days
• US Class Current: 333/156
• CPC Class Codes: H01P 1/181 using ferroelectric devices
• CPC Class Codes: H01P 1/184 Strip line phase-shifters H01P1/181, H01P1/185, H01P1/19 take precedence
• CPC Class Codes: H01Q 21/0006 Particular feeding systems
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037
• CPC Class Codes: H01Q 25/004 providing two or four symmetrical beams for Janus application
• CPC Class Codes: H01Q 3/32 by mechanical means
• CPC Class Codes: H01Q 3/36 with variable phase-shifters

Abstract

A low-cost, steerable, phased array antenna suitable for use in wireless fidelity (WiFi) and other wireless telecommunication networks, in particular multi-hop ad hoc networks, is disclosed. Various embodiments of an antenna assembly that includes a plurality of linear phased array antennas fed by corporate feeds are disclosed. The corporate feeds are implemented as parallel wire transmission lines, such as a coaxial, stripline, microstrip, or coplanar waveguide (CPW) transmission line. Selected branches of the corporate feed network include transmission line phase shifters oriented and sized so as to allow a high-permittivity dielectric element to control phase shifting. Thus, the corporate feed forms a phase shifting feed whose phase shift is controllable. Phase shifting can be electromechanically controlled by controlling the space between the high-permittivity dielectric element and the phase shifting branches of the corporate feed or by electrically controlling the permittivity of the high-permittivity dielectric element.

Claims

1. A low-cost, steerable, phased array antenna comprising:

a plurality of antenna elements;

a corporate feed connected to said antenna elements, said corporate feed including a plurality of phase shift transmission lines;

a high-permittivity dielectric element overlying said plurality of phase shift transmission lines of said corporate feed; and

a controller for controlling the interaction of the permittivity of the high-permittivity dielectric element with the plurality of phase shift transmission lines of the corporate feed.

2. A low-cost, steerable, phased array antenna as claimed in claim 1 wherein said plurality of antenna elements are linearly arrayed.

3. A low cost, steerable, phased array antenna as claimed in claim 1, including a dielectric sheet and wherein said corporate feed is located on a surface of said dielectric sheet.

4. A low cost, steerable phased array antenna as claimed in claim 3 wherein said plurality of antenna elements are also located on a surface of said dielectric sheet.

5. A low-cost, steerable, phased array antenna as claimed in claim 4 wherein said plurality of antenna elements and said corporate feed are located on the same surface of said dielectric sheet.

6. A low-cost, steerable, phased array antenna as claimed in claim 5, including:

a second plurality of antenna elements and a second corporate feed located on the other surface of said dielectric sheet, said second corporate feed connected to said second plurality of antenna elements, said second corporate feed including a plurality of phase shift transmission lines; and

a second high-permittivity dielectric element overlying said plurality of phase shift transmission lines, said controller controlling the interaction of the permittivity of said second high-permittivity dielectric element with said plurality of phase shift transmission lines of said second corporate feed.

7. A low-cost, steerable, phased array antenna as claimed in claim 4 wherein said dielectric sheet is a printed circuit board sheet and wherein said plurality of antenna elements and said corporate feed are created by printing said antenna elements and said corporate feed on said printed circuit board.

8. A low-cost, steerable, phased array antenna as claimed in claim 1 wherein said high-permittivity dielectric element is formed of a material chosen from the group consisting of Rutile (Titanium Dioxide) and compounds of Rutile containing alkali earth metals.

9. A low-cost, steerable, phased array antenna as claimed in claim 8 wherein said alkali earth metals are chosen from the group consisting of Barium and Strontium.

10. A low-cost, steerable, phased array antenna as claimed in claim 1 wherein said controller for controlling the interaction of the permittivity of the high-permittivity dielectric element on said plurality of phase shift transmission lines of said corporate feed includes an electromechanical system for controlling the position of said high-permittivity dielectric element with respect to said plurality of phase shift transmission lines of said corporate feed.

11. A low-cost, steerable, phased array antenna as claimed in claim 10 wherein said high-permittivity dielectric element is a planar layer that includes a high-permittivity dielectric material and wherein said layer is positioned with respect to said plurality of phase shift transmission lines of said corporate feed by moving said layer toward and away from said phase shift transmission lines.

12. A low-cost, steerable, phased array antenna as claimed in claim 11 wherein said high-permittivity dielectric layer comprises a supporting layer formed of a dielectric material and a plurality of slugs mounted on said dielectric supporting layer.

13. A low-cost, steerable, phased array antenna as claimed in claim 11 wherein said high-permittivity dielectric layer is a self supporting layer.

14. A low-cost, steerable, phased array antenna as claimed in claim 10 wherein said high-permittivity dielectric element is a cylinder that includes a high-permittivity material and wherein said cylinder is positioned with respect to said plurality of phase shift transmission lines of said corporate feed by rotating said cylinder along an axis offset from the axis of said cylinder.

15. A low-cost, steerable, phased array antenna as claimed in claim 1 wherein said high-permittivity dielectric element is formed of a ferroelectric material and wherein said controller for controlling the interaction of the permittivity of the high-permittivity dielectric element on said plurality of phase shift transmission lines of said corporate feed controls the application of electrical energy to said ferroelectric material.

16. A low-cost, steerable, phased array antenna as claimed in claim 1 wherein said plurality of antenna elements is eight elements and wherein said plurality of phase shift transmission lines include a long phase shift transmission line, two intermediate length phase shift transmissions lines, and four short transmission lines.

17. A low-cost, steerable, phased array antenna as claimed in claim 16 wherein the length of said intermediate phase shift transmission lines is one-half the length of said long phase shift transmission line, and wherein the length of said short phase shift transmission lines is one-half the length of said intermediate phase shift transmission lines.

18. A low-cost, steerable, phased array antenna as claimed in claim 17 wherein said short phase shift transmission lines are coaxially arrayed, said intermediate length phase shift transmission lines are coaxially arrayed, and wherein said long transmission lines, said intermediate phase shift transmission lines, and said short phase shift transmission lines lie parallel to one another.

19. A low-cost, steerable, phased array antenna as claimed in claim 18 wherein said long transmission line is connected to one of said antenna elements, to one of said intermediate phase shift transmission lines, and to one of said short phase shift transmission lines, said one of said short phase shift transmission lines is connected to another of said antenna elements, said one of said intermediate phase shift transmission lines is connected to a further one of said antenna elements and to a second of said short phase shift transmission lines, said second of said short phase shift transmission lines is connected to a further one of said antenna elements, the second of said intermediate phase shift transmission lines is connected to a further one of said antenna elements and to a third of said short phase shift transmission lines, said third of said short phase shift transmission lines is connected to an additional antenna element, said fourth phase shift transmission line is connected to an additional element of said antenna elements, said long transmission line, said second of said intermediate transmission lines and said fourth of said short phase transmission lines are connected to a terminal and to the remaining one of said eight antenna elements.

20. A low-cost, steerable, 360°

phased array antenna comprising;

a) an L-shaped housing;

b) four linear phased array antennas, two of said antennas mounted in each leg of said L-shaped housing so as to point in opposite directions, each of said linear phased array antennas comprising;

i) a dielectric sheet;

ii) a plurality of antenna elements located on a surface of said dielectric sheet;

iii) a corporate feed connected to said antenna elements, said corporate feed located on a surface of said dielectric sheet, said corporate feed including a plurality of phase shift transmission lines; and

iv) a high-permittivity dielectric element overlying said plurality of phase shift transmission lines of said corporate feed; and

c) a controller for controlling the interaction of the permittivity of the high-permittivity dielectric elements with the plurality of phase shift transmission lines of the corporate feed that the high-permittivity dielectric elements overlie.

21. A low-cost, steerable, 360°

phased array antenna as claimed in claim 20 wherein said plurality of antenna elements and said corporate feed are located on the same surface of said dielectric sheet.

22. A low-cost, steerable, 360°

phased array antenna as claimed in claim 21 wherein said dielectric sheet is common to the linear phased array antennas in the same one of the legs of the L-shaped housing.

23. A low-cost, steerable, 360°

phased array antenna as claimed in claim 20 wherein said dielectric sheet is a printed circuit board sheet and wherein said plurality of antenna elements and said corporate feed are created by printing said antenna elements and said corporate feed on said printed circuit board.

24. A low-cost, steerable, 360°

phased array antenna as claimed in claim 20 wherein said high-permittivity dielectric element is formed of a material chosen from the group consisting of Rutile (Titanium Dioxide) and compounds of Rutile containing alkali earth metals.

25. A low-cost, steerable, 360°

phased array antenna as claimed in claim 24 wherein said alkali earth metals are chosen from the group consisting of Barium and Strontium.

26. A low-cost, steerable, 360°

phased array antenna as claimed in claim 20 wherein said controller for controlling the interaction of the permittivity of the high-permittivity dielectric element on said plurality of phase shift transmission lines of said corporate feed includes an electromechanical system for controlling the position of said high-permittivity dielectric element with respect to said plurality of phase shift transmission lines of said corporate feed.

27. A low-cost, steerable, 360°

phased array antenna as claimed in claim 26 wherein said high-permittivity dielectric element is a planar layer that includes a high-permittivity dielectric material and wherein said layer is positioned with respect to said plurality of phase shift transmission lines of said corporate feed by moving said layer toward and away from said phase shift transmission lines.

28. A low-cost, steerable, 360°

phased array antenna as claimed in claim 27 wherein said high-permittivity dielectric layer comprises a supporting layer formed of a dielectric material and a plurality of slugs mounted on said dielectric supporting layer.

29. A low-cost, steerable, 360°

phased array antenna as claimed in claim 27 wherein said high-permittivity dielectric layer is a self supporting layer.

30. A low-cost, steerable, 360°

phased array antenna as claimed in claim 26 wherein said high-permittivity dielectric element is a cylinder that includes a high-permittivity material and wherein said cylinder is positioned with respect to said plurality of phase shift transmission lines of said corporate feed by rotating said cylinder along an axis offset from the axis of said cylinder.

31. A low-cost, steerable, 360°

phased array antenna as claimed in claim 20 wherein said high-permittivity dielectric element is formed of a ferroelectric material and wherein said controller for controlling the interaction of the permittivity of the high-permittivity dielectric element on said plurality of phase shift transmission lines of said corporate feed controls the application of electrical energy to said ferroelectric material.

32. A low-cost, steerable, 360°

phased array antenna as claimed in claim 20 wherein said plurality of antenna elements is eight elements and wherein said plurality of phase shift transmission lines include a long phase shift transmission line, two intermediate length phase shift transmissions lines, and four short transmission lines.

33. A low-cost, steerable, 360°

phased array antenna as claimed in claim 32 wherein the length of said intermediate phase shift transmission lines is one-half the length of said long phase shift transmission line, and wherein the length of said short phase shift transmission lines is one-half the length of said intermediate phase shift transmission lines.

34. A low-cost, steerable, 360°

phased array antenna as claimed in claim 33 wherein said short phase shift transmission lines are coaxially arrayed, said intermediate length phase shift transmission lines are coaxially arrayed, and wherein said long transmission line, said intermediate phase shift transmission lines, and said short phase shift transmission lines lie parallel to one another.

35. A low-cost, steerable, 360°

phased array antenna as claimed in claim 34 wherein said long transmission line is connected to one of said antenna elements, to one of said intermediate phase shift transmission lines, and to one of said short phase shift transmission lines, said one of said short phase shift transmission lines is connected to another of said antenna elements, said one of said intermediate phase shift transmission lines is connected to a further one of said antenna elements and to a second of said short phase shift transmission lines, said second of said short phase shift transmission lines connected to a further one of said antenna elements, the second of said intermediate phase shift transmission lines is connected to a further one of said antenna elements and to a third of said short phase shift transmission lines, said third of said short phase shift transmission lines is connected to an additional antenna element, said fourth phase shift transmission line is connected to an additional element of said antenna elements, said long transmission line, said second of said intermediate transmission lines and said fourth of said short phase transmission lines are connected to a terminal and to the remaining one of said eight antenna elements.

36. A low-cost corporate feed suitable for use in a phased array antenna comprising:

a plurality of phase shift transmission lines;

a high-permittivity dielectric element overlying said plurality of phase shift transmission lines; and

a controller for controlling the interaction of the permittivity of the high-permittivity dielectric element with the plurality of phase shift transmission lines of said corporate feed.

37. A low-cost corporate feed as claimed in claim 36, including a dielectric sheet, said plurality of phase shift transmission lines being located on one surface of said dielectric sheet.

38. A low-cost corporate feed as claimed in claim 36 wherein said high-permittivity dielectric element is formed of a material chosen from the group consisting of Rutile (Titanium Dioxide) and compounds of Rutile containing alkali earth metals.

39. A low-cost corporate feed as claimed in claim 38 wherein said alkali earth metals are chosen from the group consisting of Barium and Strontium.

40. A low-cost corporate feed as claimed in claim 36 wherein said controller for controlling the interaction of the permittivity of the high-permittivity dielectric element on said plurality of phase shift transmission lines of said corporate feed includes an electromechanical system for controlling the position of said high-permittivity dielectric element with respect to said plurality of phase shift transmission lines of said corporate feed.

41. A low-cost corporate feed as claimed in claim 36 wherein said high-permittivity dielectric element is a planar layer that includes a high-permittivity dielectric material and wherein said layer is positioned with respect to said plurality of phase shift transmission lines of said corporate feed by moving said layer toward and away from said phase shift transmission lines.

42. A low-cost corporate feed as claimed in claim 41 wherein said high-permittivity dielectric layer comprises a supporting layer formed of a dielectric material and a plurality of slugs mounted on said dielectric supporting layer.

43. A low-cost corporate feed as claimed in claim 41 wherein said high-permittivity dielectric layer is a self supporting layer.

44. A low-cost corporate feed as claimed in claim 36 wherein said high-permittivity dielectric element is a cylinder that includes a high-permittivity material and wherein said cylinder is positioned with respect to said plurality of phase shift transmission lines of said corporate feed by rotating said cylinder along an axis offset from the axis of said cylinder.

45. A low-cost corporate feed as claimed in claim 36 wherein said high-permittivity dielectric element is formed of a ferroelectric material and wherein said controller for controlling the interaction of the permittivity of the high-permittivity dielectric element on said plurality of phase shift transmission lines of said corporate feed controls the application of electrical energy to said ferroelectric material.

46. A low-cost corporate feed as claimed in claim 36 wherein said dielectric sheet is a printed circuit board sheet and wherein said corporate feed is created by printing said corporate feed on said printed circuit board.

47. A low-cost corporate feed as claimed in claim 36 wherein said plurality of phase shift transmission line comprises a long phase shift transmission line, two intermediate length phase shift transmissions lines, and four short transmission lines.

48. A low-cost corporate feed as claimed in claim 47 wherein the length of said intermediate phase shift transmission lines is one-half the length of said long phase shift transmission line, and wherein the length of said short phase shift transmission lines is one-half the length of said intermediate phase shift transmission lines.

49. A low-cost corporate feed as claimed in claim 48 wherein said short phase shift transmission lines are coaxially arrayed, said intermediate length phase shift transmission lines are coaxially arrayed, and wherein said long transmission line, said intermediate phase shift transmission lines, and said short phase shift transmission lines lie parallel to one another.

50. A low-cost corporate feed as claimed in claim 49 wherein said long transmission line is connected to one of said intermediate phase shift transmission lines and to one of said short phase shift transmission lines, said one of said intermediate phase shift transmission lines is connected to a second of said short phase shift transmission lines, and the second of said intermediate phase shift transmission lines is connected to a third of said short phase shift transmission lines.