Microelectromechanical phased array antenna

• US 6,653,985 B2
• Filed: 09/17/2001
• Issued: 11/25/2003
• Est. Priority Date: 09/15/2000
• Status: Expired due to Term

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Chang, Yueh-Chi, Sikina, Thomas V.
• Primary Examiner(s): LE, HOANGANH T
• Application Number:
  US09/954,516
• Publication Number:
  US 20030184476A1
• Time in Patent Office: 799 Days
• Field of Search: H01/Q 2.100, 343/700.MS, 343/853, 343/895, 343/767, 343/770, 343/771
• US Class Current: 343/853
• CPC Class Codes: H01Q 21/0031 Parallel-plate fed arrays; Lens-fed arrays multibeam arrays H01Q25/008
• CPC Class Codes: H01Q 21/0087 Apparatus or processes specially adapted for manufacturing antenna arrays manufacturing waveguides H01P11/00
• CPC Class Codes: H01Q 3/36 with variable phase-shifters
• CPC Class Codes: H01Q 3/46 Active lenses or reflecting arrays

Abstract

An array antenna includes a radiator layer having first and second opposing surfaces and a plurality of radiators disposed on a first surface of the radiator layer. Additionally the antenna includes a microelectromechanical systems (MEMS) layer with a plurality of MEMS phase shifters disposed adjacent to the second surface of the radiator layer, each one of the plurality of MEMS phase shifters electromagnetically coupled to at least one of the plurality of radiators. Finally, a beamformer layer is electromagnetically coupled to the MEMS layer, and a spacer layer is disposed between the MEMS layer and the beamformer layer. A second embodiment is provided from multiple layers and utilizes a plurality of subarray structures which are coupled to form the entire array aperture.

Claims

1. An antenna comprising:

a radiator layer having a first surface and a second opposing surface;

a first plurality of radiators disposed on the first surface of the radiator layer;

a microelectromechanical systems (MEMS) layer having a plurality of MEMS phase shifters disposed adjacent to the second surface of the radiator layer, each of the plurality of MEMS phase shifters electromagnetically coupled to at least one of the first plurality of radiators;

a beamformer layer electromagnetically coupled to the MEMS layer; and

a spacer layer disposed between the MEMS layer and the beamformer layer.

2. The antenna of claim 1, further comprising a second plurality of radiators disposed on the second surface of the radiator layer, electromagnetically coupled to at least one of the first plurality of radiators and to at least one of the plurality of MEMS phase shifters.

3. The antenna of claim 1, wherein the radiator layer further comprises a plurality of polarizing circuits coupled to respective ones of the first plurality of radiators.

4. The antenna of claim 3 wherein each of the plurality of polarizing circuits comprises a hybrid circuit disposed between the MEMS layer and a respective radiator.

5. The antenna of claim 1 wherein the beamformer layer comprises a radial waveguide beamformer.

6. The antenna of claim 5 wherein the radial waveguide beamformer is a parallel plate radial waveguide beamformer.

7. The antenna of claim 1 wherein the first plurality of radiators is arranged in a radial pattern.

8. The antenna of claim 1 wherein the first plurality of radiators comprises a plurality of circularly polarized slot patch radiators.

9. The antenna of claim 8 wherein each of the plurality of circularly polarized slot patch radiators has a probe coupled to the MEMS layer.

10. The antenna of claim 8 wherein each of the plurality of circularly polarized slot fed patch radiators has an aperture electromagnetically coupled to the MEMS layer.

11. The antenna of claim 10 further comprising a 4-aperture circularly polarized hybrid circuit.

12. The antenna of claim 10 further comprising a 2-aperture circularly polarized hybrid circuit.

13. The antenna of claim 1 wherein the first plurality of radiators comprises a plurality of dual stacked patch radiators.

14. The antenna of claim 1 wherein the first plurality of radiators comprises a plurality of spiral patch radiators.

15. The antenna of claim 14 wherein each of the plurality of spiral patch radiators comprises a plurality of spiral traces.

16. The antenna of claim 1 further comprising a common radome having a transmit aperture and a receive aperture such that the antenna provides a transmit array and a receive array.

17. The antenna of claim 1 wherein the MEMS layer and the first plurality of radiators are coupled by at least one electromagnetic connection, such connection provided by at least one of:

a space feed; and

a probe coupling mechanism.

18. The antenna of claim 17 wherein the space feed is provided as a plurality of apertures provided in the MEMS layer such that RF energy is coupled from the beamformer layer through the apertures to respective ones of the radiators.

19. The antenna of claim 18 wherein the MEMS layer further comprises a stripline transmission circuit coupled to the plurality of radiators and coupled to the plurality of MEMS phase shifters.

20. The antenna of claim 18 wherein each of the plurality of radiators is a substantially circular shaped patch radiator having a center;

and

each of the respective plurality of apertures comprises a rectangular shaped slot having a slot center.

21. The antenna of claim 20 wherein the patch center is offset from the slot center.

22. The antenna of claim 21 further comprising:

a probe coupled to the patch offset from the patch center; and

and a coupling feature coupled to the probe and disposed between the patch and the slot.

23. The antenna of claim 17 wherein the probe coupling mechanism comprises a plurality of probes disposed in the radiator layer coupled to respective one of a plurality of radiators.

24. The antenna of claim 23 wherein the MEMS layer further comprises:

a metal contact surface coupled to the plurality of probes; and

a stripline transmission circuit coupled to the metal contact surface and to the plurality of MEMS phase shifters.

25. The antenna of claim 24 further comprising a solder layer disposed between the metal contact surface and the stripline transmission circuit;

and wherein the metal contact surface is bonded to the stripline transmission circuit by solder reflow.

26. The antenna of claim 24 further comprising a conductive bonding layer disposed between the metal contact surface and the stripline transmission circuit;

and wherein the metal contact surface is bonded to the stripline transmission circuit by conductive bonding.

27. The antenna of claim 17 wherein the probe coupling mechanism comprises a plated through hole.

28. The antenna of claim 1 wherein the spacer layer comprises:

a first spacer layer surface and a second opposing spacer layer surface;

a plurality of coupling features disposed on the first spacer layer surface adjacent to the MEMS layer; and

a plurality of feeds disposed on the second spacer layer surface coupled to respective ones of the plurality of coupling features by a plurality of the probes disposed in the spacer layer between the plurality of feeds and the plurality of coupling feature.

29. The antenna of claim 28 wherein the beamformer layer comprises a

first beamformer layer surface and a second opposing beamformer layer surface;

and

a signal feed disposed on the second beamformer layer surface and electromagnetically coupled to the plurality of feeds disposed on the second spacer layer surface adjacent to the beamformer layer first surface.

30. The antenna of claim 29 wherein the signal feed comprises a coax feed.

31. The antenna of claim 1 wherein the spacer layer comprises:

a first spacer layer surface and a second opposing spacer layer surface;

a plurality of apertures disposed on the first spacer layer surface; and

a plurality of feeds disposed on the second spacer layer surface electromagnetically coupled to respective ones of the plurality of apertures.

32. The antenna of claim 31 wherein the beamformer layer further comprising a first beamformer layer surface and a second opposing beamformer layer surface and a signal feed disposed on the second beamformer layer surface and electromagnetically coupled to the plurality of feeds disposed on the second spacer layer surface.

33. The antenna of claim 32 wherein the signal feed comprises a coax feed.

34. The antenna of claim 1 wherein the beamformer layer is provided as a radial waveguide beamformer;

and

the spacer layer is provided as a foam spacer layer.

35. The antenna of claim 1 wherein the beamformer layer and the MEMS layer comprise an integrated MEMS phase shifter and radiator.

36. The antenna of claim 1 wherein each of the plurality of MEMS phase shifters further comprises a plurality of capacitive switches coupled to the radiator;

each switch having an open position and a closed position such that when the respective switch is in the closed position each of the first plurality of radiators is coupled to a respective one of a plurality of stubs disposed on the first surface of the radiator layer.

37. The antenna of claim 36 wherein the radiator comprises a patch radiator.

38. The antenna of claim 1 wherein each of the plurality of MEMS phase shifters further comprises a plurality of capacitive switches coupled to the radiator;

each switch having an open position and a closed position such that when the respective switch is in the closed position each of the first plurality of radiators is coupled to at least one of a plurality of stubs disposed on the first surface of the radiator layer.

39. The antenna of claim 1 further comprising:

a beamformer having a plurality of beamformer ports disposed on the beamformer layer; and

a plurality of diplexers having a first port, coupled to a respective plurality of beamformer ports, at least one receive port coupled to a respective one of the plurality of MEMS phase shifters, and at least one transmit port coupled to a respective one of the plurality of MEMS phase shifters.

40. An antenna comprising:

a subarray driver having a plurality of transmit circuits and a plurality of receive circuits;

a plurality of subarrays, each such subarray comprising;

a first diplexer having a transmit port and a receive port, the transmit port coupled to a respective one of the plurality of transmit circuits and the receive port coupled to a respective one of the plurality of the receive circuits;

a subarray beamforming layer having a plurality of output ports;

a plurality of second diplexers having a first port coupled to a respective one of the subarray output ports, a second port and a third port;

a microelectromechanical systems (MEMS) layer having a plurality of pairs of MEMS phase shifters, each of a second one of the pair coupled to a respective one of the second port of second diplexers, and each of a first one of the pair coupled to a respective one of the third port of second diplexers; and

a plurality of radiators disposed on a radiator layer, each of the plurality of radiators coupled to a respective pair of MEMS phase shifters.

41. The antenna of claim 40 further comprising a radome have relatively minimal attenuation disposed on the plurality of subarrays.

42. The antenna of claim 40 wherein the subarray beamformer layer comprises a plurality of orthogonal N:

1 beamformers.

43. The antenna of claim 40 wherein the subarray driver further comprises an E-plane tee beamformer.

44. The antenna of claim 43 wherein the E-plane tee beamformer comprises a plurality of conductive and relatively low loss foam layers.

45. The antenna of claim 44 wherein the E-plane tee beamformer further comprises an N:

1 waveguide divider.

46. The antenna of claim 40 wherein the subarray driver further comprises:

a plurality of N;

1 receive beamformers having a plurality of receive input ports and a receive output port coupled to a down converter; and

a plurality of M;

1 transmit beamformers having a plurality of transmit output ports and a transmit input port coupled to an up converter.

47. The antenna of claim 46 wherein the subarray driver further comprises:

a plurality of transmit time delay units, each transmit time delay unit coupled to a respective one of a plurality of transmit amplifiers and to a respective one of the plurality of transmit output ports; and

a plurality of receive time delay units, each time delay unit coupled to a respective one of a plurality of receive amplifiers and to a respective one of the plurality of transmit output ports.

48. The antenna of claim 40 wherein the MEMS layer and the radiator layer are coupled using a plurality of apertures.

49. The antenna of claim 40 wherein the MEMS layer and the radiator layer are coupled using a plurality of probes.

50. The antenna of claim 40 wherein the MEMS layer and the first plurality of radiators are coupled by at least one electromagnetic connection, such connection provided by at least one of:

a space feed; and

a probe coupling mechanism.

51. The antenna of claim 40 wherein each subarray driver further comprises a spacer layer comprising:

first a space layer surface and a second opposing spacer layer surface;

a plurality of coupling features disposed on the first spacer layer surface adjacent to the MEMS layer; and

a plurality of feeds disposed on the second spacer layer surface coupled to respective ones of the plurality of coupling features by a plurality of the probes disposed in the spacer layer between the plurality of feeds and the plurality of coupling features.

52. The antenna of claim 40 wherein each of the plurality of MEMS phase shifters further comprises a plurality of capacitive switches coupled to the radiator, each switch having an open position and a closed position such that when the respective switch is in the closed position each of the first plurality of radiators is coupled to a respective one of a plurality of stubs disposed on the first surface of the radiator layer.

53. The antenna of claim 40 further comprising a plurality of hybrid circuits, each of the plurality of hybrid circuits disposed between the MEMS layer and a respective on of the plurality of radiators and coupled to a respective pair of the plurality of MEMS phase shifters.

54. The antenna of claim 53 wherein the hybrid circuit provides circularly polarized radio frequency energy.

55. The antenna of claim 40 wherein the driver further comprised an array direct current and controller module coupled to a time delay unit and driver multiplexer module.

56. The antenna of claim 55 wherein each of the plurality of subarrays further comprises a multiplexer coupled to the plurality of pairs of MEMS phase shifters.

57. The antenna of claim 40 wherein the subarray driver further comprises a feed layer having a column beamformer circuit layer disposed on a row beamformer circuit layer disposed on a MEMS control card layer disposed on an 10:

1 beamformer circuit layer.

58. The antenna of claim 40 wherein the MEMS layer further comprises a MEMS transfer stripline layer.

59. The antenna of claim 40 wherein the radiator layer further comprises:

a row balun layer; and

a column balun layer disposed on the row balun layer.

60. The antenna of claim 40 wherein the radiator layer further comprises a dual stacked patch radiator layer.

61. An antenna comprising:

a subarray driver;

a plurality of subarrays, each such subarray comprising;

a plurality of output ports and, a plurality of input ports;

a microelectromechanical systems (MEMS) layer having a plurality of MEMS phase shifters, each of the plurality of MEMS phase shifters coupled to a respective one of the subarray outputs; and

a plurality of radiators disposed on a radiator layer, each of the plurality of radiators coupled to a respective one of the plurality of MEMS phase shifters.

62. The antenna of claim 61 comprising a transmit amplifier disposed between the subarray driver and each of the plurality of subarrays.

63. The antenna of claim 61 comprising a receive amplifier disposed between the subarray driver and each of the plurality of subarrays.

64. The antenna of claim 61 wherein the plurality of subarrays are arranged in a plurality of rows and a plurality of columns.