Microelectromechanical systems (MEMS) switch and related methods
Microelectromechanical systems (MEMS) switches are disclosed. The MEMS switch may have an actuation voltage greater than the expected voltage of a signal being passed by the MEMS switch in normal operation. The MEMS switches may include a distributed hinge structure in some embodiments. Radial contact pads are included in some embodiments, with or separate from the distributed hinge.
1. A microelectromechanical systems (MEMS) switch, comprising:
a substrate;
an anchor coupled to the substrate;
a beam coupled to the anchor by a plurality of hinges and suspended above the substrate; and
a plurality of electrodes disposed on the substrate and including a first electrode configured to receive an actuation voltage and a second electrode configured to apply a signal to the beam, the actuation voltage being greater than a maximum voltage of the signal applied to the beam.
2. The MEMS switch of claim 1 , wherein the second electrode is configured to apply a radiofrequency signal to the beam.
3. The MEMS switch of claim 1 , wherein the plurality of hinges are configured to prevent closing of the MEMS switch when the actuation voltage is not at least twice as large as the maximum voltage of the signal applied to the beam.
4. The MEMS switch of claim 1 , wherein the beam comprises a contact electrode configured to contact the second electrode when the MEMS switch is closed.
5. The MEMS switch of claim 1 wherein the plurality of hinges comprises multiple hinges coupled to a same side of the anchor.
6. The MEMS switch of claim 5 , wherein the plurality of hinges comprises four hinges coupled to the same side of the anchor.
7. The MEMS switch of claim 6 , wherein the plurality of hinges are in-plane with and parallel to a length of the beam.
8. The MEMS switch of claim 7 , wherein the MEMS switch does not include any hinges perpendicular to the beam.
9. A method of operating a microelectromechanical systems (MEMS) switch, comprising:
applying a signal to a beam of the MEMS switch; and
applying an actuation voltage to a first electrode on a substrate underlying the beam of the MEMS switch, wherein the actuation voltage is at least twice as large as a maximum voltage of the signal applied to the beam.
10. The method of claim 9 , wherein applying the actuation voltage to the first electrode comprises applying a voltage at least three times greater than the maximum voltage of the signal applied to the beam.
11. The method of claim 9 , wherein applying the actuation voltage to the first electrode comprises applying a voltage between two and ten times greater than the maximum voltage of the signal applied to the beam.
12. The method of claim 9 , wherein applying the actuation voltage to the first electrode comprises maintaining the actuation voltage at a value at least twice as large as a maximum voltage of the signal applied to the beam while the MEMS switch is closed.
13. The method of claim 9 , further comprising opening the MEMS switch by reducing the actuation voltage to a value less than twice as large as the maximum voltage of the signal applied to the beam.
14. A microelectromechanical systems (MEMS) teeter-totter switch, comprising:
a substrate;
an anchor;
a beam suspended above the substrate, coupled to the anchor and configured to pivot about the anchor, wherein the anchor comprises four or more substantially parallel tethers attached to the beam;
a contact pad on the substrate;
a radially symmetric metallization on the contact pad; and
a plurality of electrodes disposed on the substrate and including a first electrode configured to receive an actuation voltage and a second electrode configured to apply a signal to the beam, the actuation voltage being greater than a maximum voltage of the signal applied to the beam.
15. The MEMS teeter-totter switch of claim 14 , wherein the four or more tethers comprises two tethers on either side of the anchor.
16. The MEMS teeter-totter switch of claim 14 , wherein the four or more tethers comprises four tethers on a same side of the anchor.
17. The MEMS teeter-totter switch of claim 14 , wherein the radially symmetric metallization has a thickness between 50 microns and 200 microns.
18. The MEMS teeter-totter switch of claim 17 , wherein the radially symmetric metallization has a semi-circular contour.
19. The MEMS teeter-totter switch of claim 18 , wherein the beam comprises a contact electrode configured to contact the contact pad on the substrate at a location representing a center of the semi-circular contour.
20. The MEMS teeter-totter switch of claim 19 , wherein the center of the semi-circular contour is between 1 micron and 5 microns from the semi-circular contour.