MMIC airbridge balun transformer

• US 6,476,704 B2
• Filed: 07/09/2001
• Issued: 11/05/2002
• Est. Priority Date: 11/18/1999
• Status: Expired due to Term

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Goff, Miles E.
• Primary Examiner(s): MAI, ANH T
• Application Number:
  US09/901,530
• Publication Number:
  US 20010035809A1
• Time in Patent Office: 484 Days
• Field of Search: 336/182, 336/200, 336/223, 336/232, 336/186, 336/187, 296/021, 296/06, 296/05
• US Class Current: 336/200
• CPC Class Codes: H01F 17/0006 Printed inductances printed coils for dynamo-electric machines H02K3/26; printed circuits H05K
• CPC Class Codes: H01F 2017/0046 with a conductive path having a bridge
• CPC Class Codes: H01L 2223/6672 for integrated passive components, e.g. semiconductor device with passive components only
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 23/645 Inductive arrangements H01L23/647, H01L23/66 take precedence
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49073 by assembling coil and core

Abstract

A balun transformer and inductor are proposed having geometries that provide several windings of conductors in small areas. In one embodiment, the windings of the balun transformer and inductor have octagonal shapes with a lower and upper layer of wound conductors. The upper layer lies on supporting posts that stand on pedestals. The lower layer of conductors shadow the upper layer while curving to avoid the pedestals.

Claims

1. A balun transformer, comprising:

a primary conductor, wherein said primary conductor comprises at least one primary winding having at least one planar portion and at least one primary crossover portion, and wherein said at least one planar portion of said at least one primary winding lies within a first plane;

a secondary conductor, wherein said secondary conductor comprises at least one secondary winding having at least one planar portion and at least one secondary crossover portion, and wherein said at least one planar portion of said at least one secondary winding lies within a second plane located above said first plane, and further wherein said at least one planar portion of said at least one secondary winding is concentrical;

at least one supporting post to support said at least one planar portion of said at least one secondary winding; and

a dielectric comprising air disposed between said first plane and said second plane.

2. A balun transformer in accordance with claim 1, wherein said at least one planar portion of said at least one secondary winding winds along a polygonal path and wherein said at least one secondary crossover portion crosses from an outward secondary winding to an inward secondary winding.

3. A balun transformer in accordance with claim 2, wherein said at least one planar portion of said at least one secondary winding completes a one-half turn.

4. A balun transformer in accordance with claim 3, wherein said polygonal path is an octagonal path.

5. A balun transformer in accordance with claim 1, wherein said at least one planar portion of said at least one secondary winding lies approximately one micron above said at least one planar portion of said at least one primary winding.

6. A balun transformer in accordance with claim 1, wherein said primary conductor is wider than said secondary conductor.

7. A balun transformer in accordance with claim 1, wherein said primary conductor curves around said at least one supporting post to avoid said at least one supporting post.

8. A balun transformer in accordance with claim 1, further comprising:

at least one pedestal, wherein said at least one pedestal supports said at least one supporting post.

9. A balun transformer in accordance with claim 8, wherein said primary conductor curves around said at least one pedestal to avoid said at least one pedestal.

10. A balun transformer in accordance with claim 1, wherein said primary conductor and said secondary conductor are comprised of gold, and further wherein said primary conductor is approximately one micron thick and said secondary conductor is approximately three microns thick.

11. A balun transformer in accordance with claim 10, wherein said at least one planar portion of said at least one secondary winding lies approximately one micron above said at least one planar portion of said at least one primary winding.

12. A balun transformer in accordance with claim 1, wherein said dielectric further comprises one of the following:

silicone nitride and polyimide.

13. A balun transformer in accordance with claim 1, wherein said at least one planar portion of said at least one secondary winding winds along a circular path and wherein said at least one secondary crossover portion crosses from an outward secondary winding to an inward secondary winding.

14. A balun transformer in accordance with claim 13, wherein said at least one planar portion of said at least one secondary winding completes a one-half turn.

15. An inductor, comprising:

a primary conductor comprising at least one planar portion and at least one primary crossover portion, wherein said at least one planar portion of said primary conductor lies within a first plane;

a secondary conductor electrically connected to said primary conductor wherein said secondary conductor comprises at least one planar portion and at least one secondary crossover portion, and wherein said at least one planar portion of said secondary conductor lies within a second plane located above said first plane, and further wherein said at least one planar portion of said secondary conductor is concentrical;

a dielectric comprising air disposed between said first plane and said second plane; and

at least one supporting post to support said at least one planar portion of said secondary conductor, wherein said at least one planar portion of said primary conductor curves around said at least one supporting post to avoid said at least one supporting post, and wherein said primary conductor and said secondary conductor comprise more than one winding of a conductor.

16. An inductor in accordance with claim 15, wherein said at least one secondary crossover portion crosses from an outward planar portion of said secondary conductor to an inward planar portion of said secondary conductor and wherein said out ward and inward planar portions of said secondary conductor wind along polygonal paths.

17. An inductor in accordance with claim 16, wherein said outward planar portion of said secondary conductor and said inward planar portion of said secondary conductor complete one-half turns.

18. An inductor in accordance with claim 16, wherein said polygonal paths are octagonal.

19. An inductor in accordance with claim 15, wherein said secondary conductor is wider than said primary conductor.

20. An inductor in accordance with claim 15, wherein said at least one planar portion of said secondary conductor lies approximately one micron above said at least one planar portion of said primary conductor.

21. An inductor in accordance with claim 15, wherein said primary conductor and said secondary conductor are comprised of gold, and further wherein said primary conductor is approximately one micron thick and said secondary conductor is approximately three microns thick.

22. An inductor in accordance with claim 21, wherein said at least one planar portion of said secondary conductor lies approximately one micron above said at least one planar portion of said primary conductor.

23. An inductor in accordance with claim 15, wherein said dielectric further comprises one of the following:

silicone nitride and polyimide.

24. An inductor in accordance with claim 15, wherein said at least one secondary crossover portion crosses from an outward planar portion of said secondary conductor to an inward planar portion of said secondary conductor and wherein said outward and inward planar portions of said secondary conductor wind along circular paths.

25. An inductor in accordance with claim 24, wherein said outward planar portion of said secondary conductor and said inward planar portion of said secondary conductor complete one-half turns.

26. A method for making balun transformers, comprising:

forming a primary conductor comprising at least one primary winding having at least one planar portion and at least one primary crossover portion;

locating said at least one planar portion of said at least one primary winding within a first plane;

forming a secondary conductor comprising at least one secondary winding having at least one concentrical planar portion and at least one secondary crossover portion;

locating at least one supporting post to support said at least one planar portion of said at least one secondary winding;

locating said at least one planar portion of said at least one secondary winding within a second plane located above said first plane; and

providing a dielectric comprising air to reside between said first plane and said second plane.

27. A method in accordance with claim 26, wherein said at least one planar portion of said at least one secondary winding is formed along a polygonal path, and wherein said at least one secondary crossover portion connects an outward secondary winding to an inward secondary winding.

28. A method in accordance with claim 27, wherein said at least one planar portion of said at least one secondary winding completes a one-half turn.

29. A method in accordance with claim 27, wherein said polygonal path is an octagonal path.

30. A method in accordance with claim 26, wherein said at least one planar portion of said at least one secondary winding is located approximately one micron above said at least one planar portion of said at least one primary winding.

31. A method in accordance with claim 26, wherein said primary conductor is formed to curve around said at least one supporting post to avoid said at least one supporting post.

32. A method in accordance with claim 26, further comprising:

providing at least one pedestal to support said at least one supporting post.

33. A method in accordance with claim 32, wherein said primary conductor is formed to curve around said at least one pedestal to avoid said at least one pedestal.

34. A method in accordance with claim 26, wherein said dielectric further comprises one of the following:

silicone nitride and polyimide.

35. A method in accordance with claim 26, wherein said at least one planar portion of said at least one secondary winding is formed along a circular path, and wherein said at least one secondary crossover portion connects an outward secondary winding to an inward secondary winding.

36. A method in accordance with claim 35, wherein said at least one planar portion of said at least one secondary winding completes a one-half turn.

37. A method for making an inductor, comprising:

forming a primary conductor comprising at least one planar portion and at least one primary crossover portion;

locating said at least one planar portion of said primary conductor within a first plane;

forming a secondary conductor comprises at least one concentrical planar portion and at least one secondary crossover portion;

providing at least one supporting post to support said at least one planar portion of said secondary conductor, wherein said at least one planar portion of said primary conductor is formed to curve around said at least one supporting post to avoid said at least one supporting post;

locating said at least one planar portion of said secondary conductor within a second plane located above said first plane;

electrically connecting said primary conductor to said secondary conductor, wherein said primary conductor and said secondary conductor comprise more than one winding of a conductor; and

providing a dielectric comprising air to reside between said first plane and said second plane.

38. A method in accordance with claim 37, wherein an outward and inward planar portions of said secondary conductor are formed along polygonal paths, and wherein said at least one secondary crossover portion connects said outward planar portion of said secondary conductor to said inward planar portion of said secondary conductor.

39. A method in accordance with claim 38, wherein said outward planar portion of said secondary conductor and said inward planar portion of said secondary conductor complete one-half turns.

40. A method in accordance with claim 38, wherein said polygonal paths are octagonal paths.

41. A method in accordance with claim 37, wherein said at least one planar portion of said secondary conductor is located approximately one micron above said at least one planar portion of said primary conductor.

42. A method in accordance with claim 37, wherein said dielectric further comprises one of the following:

silicone nitride and polyimide.

43. A method in accordance with claim 37, wherein an outward and inward planar portions of said secondary conductor are formed along circular paths, and wherein said at least one secondary crossover portion connects said outward planar portion of said secondary conductor to said inward planar portion of said secondary conductor.

44. A method in accordance with claim 43, wherein said outward planar portion of said secondary conductor and said inward planar portion of said secondary conductor complete one-half turns.