MEMS based RF components and a method of construction thereof

• US 7,292,125 B2
• Filed: 01/24/2005
• Issued: 11/06/2007
• Est. Priority Date: 01/22/2004
• Status: Expired due to Fees

• Current Assignee: Mojgan Daneshmand, Raafat R. Mansour
• Original Assignee: Mojgan Daneshmand, Raafat R. Mansour
• Inventors: Mansour, Raafat R., Daneshmand, Mojgan
• Primary Examiner(s): TAKAOKA, DEAN O
• Application Number:
  US11/039,860
• Publication Number:
  US 20050201672A1
• Time in Patent Office: 1,016 Days
• Field of Search: 333/101, 333/105, 333/108, 333/258
• US Class Current: 333/258
• CPC Class Codes: H01P 1/122 Waveguide switches
• CPC Class Codes: H01P 1/125 Coaxial switches

Abstract

A three dimensional waveguide is integrated with a MEMS structure to control a signal in various RF components. The components include switches, variable capacitors, filters and phase shifters. A controller controls movement of the MEMS structure to control a signal within the component. A method of construction and a method of operation of the component are described. The switches have high power handling capability and can be operated at high frequencies. By integrating a three dimensional waveguide with a MEMS structure, the components can be small in size with good operating characteristics.

Claims

1. A MEMS-based RF component comprising a form, said form being a three dimensional waveguide having at least one inner wall surrounding said waveguide, said at least one inner wall being conductive, said form being capable of supporting a signal and having at least one of an input and output, said form having a MEMS structure at least partially therein, said MEMS structure being constructed to control an RF signal within said form while all inner walls of said at least one inner wall remain conductive.

2. A component as claimed in claim 1 wherein said MEMS structure has a first position and a second position.

3. A component as claimed in claim 2 wherein there is a controller to control movement of said MEMS structure.

4. A component as claimed in claim 3 wherein said MEMS structure has a plurality of actuators, said actuators being movable between said first position and said second position.

5. A component as claimed in claim 3 wherein said MEMS structure is located in said waveguide.

6. A component as claimed in claim 3 wherein said MEMS structure is integrated with said waveguide.

7. A component as claimed in claim 3 wherein said waveguide is at least one of a rectangular waveguide, a coaxial waveguide, a ridge waveguide, a single ridge waveguide and a double ridge waveguide.

8. A component as claimed in claim 7 wherein the component is one selected from the group of a switch, capacitor, variable capacitor, phase shifter and filter.

9. A component as claimed in claim 3 wherein said component is a switch, said form has a signal pat and said MEMS structure is located out of said pat in said first position and at least partially within said path in said second position.

10. A component as claimed in claim 9 wherein said switch is on in said first position and off in said second position.

11. A component as claimed in claim 8 wherein said component is a switch selected from the group of an R-switch, C-switch, a T-switch, single pole single throw switch, single pole double throw switch, switch matrix and coaxial switch, planar switch and waveguide switch integrated with a planar circuit.

12. A component as claimed in claim 4 wherein said actuators are at least one selected from the group of thermal, magnetic, electrostatic, curling actuators and plastic deformation type of actuators.

13. A component as claimed in claim 6 wherein said component is a C-switch with two input ports and two output ports of said at least one of an input and an output.

14. A component as claimed in claim 6 wherein said switch is a T-switch with two input ports and two output ports of said at least one of an input and output.

15. A component as claimed in claim 6 wherein said component is an R-switch with a maximum of two input ports and two output ports of said at least one of an input and output in any single position of said switch.

16. A component as claimed in claim 6 wherein said component is a coaxial switch with at least one input and at least one output of said at least one input and output.

17. A component as claimed in claim 6 wherein said component is a single pole double throw switch having one input and two outputs of said at least one input and output.

18. A component as claimed in claim 3 wherein said component has a ridge waveguide channel therein with a gap located above a bottom plate, said MEMS structure being located beneath said gap.

19. A component as claimed in claim 18 wherein said component has a top that is sized and shaped to fit onto said bottom plate, said ridge waveguide being located in said top.

20. A component as claimed in claim 3 wherein said component has at least one input port and at least one output port of said at least one input and output, said ports having transformers located therein.

21. A component as claimed in claim 4 wherein said actuators are constructed to short circuit said signal path to turn said switch off.

22. A component as claimed in claim 10 wherein said component has more than one signal path with a MEMS structure located at each signal path, said MEMS structure having actuators that are constructed to short circuit a signal path in which the actuators are located when said signal path is off.

23. A component as claimed in claim 22 wherein said actuators are constructed to be located outside of a signal path when said signal path is on.

24. A component as claimed in claim 19 wherein said top has gold plating thereon.

25. A component as claimed in claim 4 wherein said actuators are movable up and down in a switch to provide a short between a top and bottom plate when said switch is off and to be removed entirely to a position coinciding with said inner wall of a said waveguide when said switch is on, said actuators having a capacitive loading.

26. A component as claimed in claim 4 wherein said actuators are controlled to adjust an elevation of said actuators resulting an a controllable capacitative loading of said waveguide.

27. A component as claimed in claim 4 wherein said actuators are located and constructed to provide a variable inline capacitor.

28. A component as claimed in claim 27 wherein the variable inline capacitor is located in one of a phase shifter, tunable filter, matching network and any reconfigurable system.

29. A component as claimed in claim 1 wherein said component is constructed for use in a waveband selected from the group of microwave, millimeter, terahertz and beyond.

30. A component as claimed in claim 4 wherein the component is a switch matrix comprised of a plurality of switches that are interconnected to one another, said switch matrix having a plurality of inputs and a plurality of outputs of said at least one input and output, the plurality of switches in said switch matrix having a MEMS structure with a plurality of actuators that are movable between a first position and a second position.

31. A component as claimed in claim 3 wherein said component has a configuration that is selected from the group of a planar configuration, a coplanar-waveguide configuration and low temperature cofired ceramic configuration.

32. A component as claimed in claim 1 wherein the MTEMS structure is integrated on a planar circuit.

33. A component as claimed in claim 1 wherein the component is a wide-band ridge waveguide connected into a coplanar waveguide line transition.

34. A component as claimed in claim 33 wherein said MEMS structure is integrated onto a bottom plate and a waveguide channel and ridge are fabricated on a top cover.

35. A component as claimed in claim 34 wherein a microstrip line is used as an interface to transform a ridge waveguide mode to a coplanar waveguide mode.

36. A method of constructing a MEMS-based RF component having a three dimensional waveguide with a MEMS structure at least partially therein, said waveguide having at least one wall surrounding said waveguide, said at least one wall being conductive, said method comprising constructing a base plate and a top cover that is sized and shaped to fit on said base plate, one of said base plate and said top cover having a MEMS structure incorporated therein, and affixing said cover to said plate to form said component, constructing said MEMS structure so that said at least one wall remains conducting as said MEMS structure generates.

37. A method as claimed in claim 36 including the step of incorporating the MEMS structure in said base plate and incorporating a waveguide in said cover.

38. A method as claim in claim 37 including the step of incorporating a ridge waveguide in said cover.

39. A method as claimed in claim 37 including the step of fabricating the MEMS structure, the cover and the base plate by the same process monolithically.

40. A method as claimed in claim 36 including the steps of constructing the MEMS structure separately from said cover.

41. A method of operating an RF component having a form that is a three dimensional waveguide, said waveguide having at least one inner wall surrounding said waveguide, said at least one wall being conductive, said form having a MEMS structure at least partially therein with a controller for said MEMS structure, said method comprising operating said controller to move said MEMS structure to control an RF signal within said form while all inner walls of said at least one inner wall remain conductive.