Systems and methods for providing high-capacitance RF MEMS switches

• US 8,368,491 B2
• Filed: 04/22/2010
• Issued: 02/05/2013
• Est. Priority Date: 04/22/2010
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Pillans, Brandon W., Morris, Francis J., White, Mikel J.
• Primary Examiner(s): Rojas, Bernard
• Application Number:
  US12/765,512
• Publication Number:
  US 20110259717A1
• Time in Patent Office: 1,020 Days
• Field of Search: 335/78, 200/181
• US Class Current: 335/78
• CPC Class Codes: H01G 5/16 using variation of distance between electrodes
• CPC Class Codes: H01H 11/00 Apparatus or processes specially adapted for the manufacture of electric switches processes specially adapted for manufacture of rectilinearly movable switches having a plurality of operating members associated with different sets of contacts, e.g. keyboards, H01H13/88
• CPC Class Codes: H01H 57/00 Electrostrictive relays; Piezoelectric relays
• CPC Class Codes: Y10T 29/49105 Switch making

Abstract

Systems and methods for providing high-capacitive RF MEMS switches are provided. In one embodiment, the invention relates to a micro-electro-mechanical switch assembly including a substrate, an electrode disposed on a portion of the substrate, a dielectric layer disposed on at least a portion of the electrode, a metal layer disposed on at least a portion of the dielectric layer, and a flexible membrane having first and second ends supported at spaced locations on the substrate base, where the flexible membrane is configured to move from a default position to an actuated position in response to a preselected switching voltage applied between the flexible membrane and the electrode, and where, in the actuated position, the flexible membrane is in electrical contact with the metal layer.

Claims

1. A micro-electro-mechanical switch assembly comprising:

a substrate;

an electrode disposed on a portion of the substrate;

a dielectric layer disposed on at least a portion of the electrode;

a metal layer disposed on at least a portion of the dielectric layer, wherein a top surface of the metal layer comprises a recess; and

a flexible membrane having first and second ends supported at spaced locations on the substrate base,

wherein the flexible membrane is configured to move from a default position to an actuated position in response to a preselected switching voltage applied between the flexible membrane and the electrode, and

wherein, in the actuated position, the flexible membrane is in electrical contact with the metal layer such that an air gap is formed between the metal layer and the flexible membrane at the recess.

2. The switch assembly of claim 1, wherein the metal layer is not in contact with the electrode.

3. The switch assembly of claim 1, wherein the flexible membrane is configured to return to the default position in response to removal of the preselected switching voltage.

4. The switch of claim 1, wherein a capacitive coupling, of signals traveling along the electrode to signals traveling along the flexible membrane, in the actuated position is substantially greater than the capacitive coupling in the default position.

5. The switch assembly of claim 1, wherein, in the default position, the flexible membrane is not in contact with the metal layer.

6. The switch assembly of claim 1, wherein the metal layer comprises a patterned layer.

7. The switch assembly of claim 6, wherein the patterned layer comprises a plurality of openings.

8. The switch assembly of claim 1, further comprising a bias control circuitry configured to supply the preselected switching voltage.

9. The switch assembly of claim 1, wherein the flexible membrane comprises a conductive material.

10. The switch assembly of claim 9, wherein the conductive material is a metal.

11. The switch assembly of claim 9, wherein the flexible membrane comprises aluminum.

12. The switch assembly of claim 1, wherein the dielectric layer comprises a high dielectric material.

13. The switch assembly of claim 12, wherein the dielectric layer comprises a material selected from the group consisting of silicon nitride, tantalum pentoxide, alumina, and combinations thereof.

14. The switch assembly of claim 1, wherein the first and second ends are supported using a plurality of posts.

15. The switch assembly of claim 1, wherein the top surface of the metal layer comprises a plurality of recesses.

16. The switch assembly of claim 1, wherein, in the actuated position, the flexible membrane is in electrical contact with the metal layer such that an air gap is formed between the metal layer and the flexible membrane at each of the plurality of recesses.

17. The switch assembly of claim 1, wherein the top surface of the metal layer is rough.