MICROELECTROMECHANICAL SYSTEM (MEMS) RESONANT SWITCHES AND APPLICATIONS FOR POWER CONVERTERS AND AMPLIFIERS

• US 20110067984A1
• Filed: 09/09/2010
• Published: 03/24/2011
• Est. Priority Date: 03/11/2008
• Status: Active Grant

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Regents of the University of California (University of California)
• Inventors: Kim, Bongsang, Lin, Yang, Nguyen, Clark Tu-Cuong, Li, Wei-Chang
• Granted Patent: US 9,077,060 B2
• Time in Patent Office: Days
• US Class Current: 200/181
• CPC Class Codes: H01H 1/0036 Switches making use of microelectromechanical systems [MEMS] for electromagnetic relays H01H50/005; for electrostatic relays H01H59/0009
• CPC Class Codes: H01H 50/005 using micromechanics
• CPC Class Codes: H01P 1/127 Strip line switches

Abstract

A modally driven oscillating element periodically contacts one of more electrical contacts, thereby acting as a switch, otherwise known as a resonant switch, or “resoswitch”, with very high Q'"'"'s, typically above 10000 in air, and higher in vacuum. Due to periodic constrained contacting of the contacts, the bandwidth of the switch is greatly improved. One or more oscillating elements may be vibrationally interconnected with conductive or nonconductive coupling elements, whereby increased bandwidths of such an overall switching system may be achieved. Using the resoswitch, power amplifiers and converters more closely approaching ideal may be implemented. Integrated circuit fabrication techniques may construct the resoswitch with other integrated CMOS elements for highly compact switching devices. Through introduction of specific geometries within the oscillating elements, displacement gains may be made where modal deflections are greatly increased, thereby reducing device drive voltages to 2.5 V or lower.

Claims

1. An oscillating switch apparatus, comprising:

a) a substrate, and

b) means for switching disposed on the substrate.

2. The apparatus of claim 1, wherein the means for switching comprises:

a) a driven element that oscillates;

b) one or more switch contacts proximal to the driven element;

c) one or more drive electrodes proximal to the driven element;

d) wherein the driven element contacts at least one of the switch contacts upon a sufficient amplitude oscillation imparted by the drive electrodes.

3. A power amplifier comprising at least one of the oscillating switch apparatus of claim 1.

4. A power converter comprising at least one of the oscillating switch apparatus of claim 1.

5. The apparatus of claim 2, wherein the driven element comprises:

a) a conductor spaced above the substrate;

b) one or more electrodes that act to impart a vibration on the conductor;

c) one or more contact electrodes that are periodically electrically connected to the conductor within a bandwidth of vibration of the conductor.

6. The apparatus of claim 1, wherein the means for switching comprises:

a) a driven element that oscillates, wherein the driven element is spaced apart from the substrate, and connected to the substrate;

b) two switch contacts proximal to the driven element;

c) two drive electrodes proximal to the driven element;

d) wherein the two drive elements generate oscillations in the driven element; and

e) the oscillations cause modal deflections in the driven element, whereby the driven element periodically electrically connects the two switch contacts.

7. The apparatus of claim 6, wherein the driven element is driven within its operational bandwidth to periodically electrically connect the two switch contacts.

8. The apparatus of claim 2, wherein the driven element is polysilicon or a metal.

9. The apparatus of claim 2, wherein the driven element is driven with a voltage amplitude of less than or equal to 3 volts.

10. The apparatus of claim 9, wherein the oscillating switch apparatus has a switch closure time of less than 10 ns.

11. The apparatus of claim 9, wherein the oscillating switch apparatus has a switch closure time of less than 5 ns.

12. The apparatus of claim 9, wherein the oscillating switch apparatus has a switch closure time approximately 4 ns.

13. The apparatus of claim 2, wherein a gap between the driven element and the drive electrode is 150 nm or less.

14. The apparatus of claim 2, wherein a gap between the driven element and the drive electrode is 100 nm or less.

15. The apparatus of claim 2, wherein a gap between the driven element and the switch contacts is 150 nm or less.

16. The apparatus of claim 2, wherein a gap between the driven element and the switch contacts is 100 nm or less.

17. The apparatus of claim 2, wherein the driven element has an unconstrained resonant frequency between 61 MHz and 2.0 GHz.

18. The apparatus of claim 2, wherein the oscillating switch has a Q of 10000 or greater.

19. The apparatus of claim 2, wherein the oscillating switch has a Q of 12500 or greater.

20. The apparatus of claim 19, wherein the oscillating switch operates an ambient gas selected from the group of gasses consisting of:

vacuum, air, nitrogen, argon, SF₆.

21. The apparatus of claim 2, wherein the oscillating switch is monolithically fabricated along with one or more CMOS elements.

22. The apparatus of claim 2, wherein the driven element is substantially circular.

23. The apparatus of claim 22, wherein the driven element oscillates in wine-glass mode.

24. The apparatus of claim 2, wherein the driven element is substantially flat.

25. The apparatus of claim 2, wherein the driven element comprises one or more displacement gain elements.

26. A cascaded resonator, comprising two or more of the apparatus of claim 25 interconnected with resonant structures, wherein the bandwidth of the cascaded resonator exceeds the bandwidth of the individual oscillating switch apparatus of claim 25.

27. An oscillating switch, comprising:

a) a substrate;

b) one or more driven elements spaced above and connected to the substrate;

c) one or more drive electrodes proximal to at least one driven element;

d) one or more switch contacts proximal to at least one driven element;

e) wherein at least one drive electrode oscillates at least one driven element;

f) wherein at least one driven element periodically electrically connects with one or more switch contacts.

28. The apparatus of claim 27, comprising:

a) a physical connection between two or more of the driven elements, wherein the oscillation of at least one of the driven elements is transmitted to at least one other driven element.

29. The apparatus of claim 28, wherein the physical connection is disposed above the substrate.

30. The apparatus of claim 28, wherein the physical connection is a beam.

31. The apparatus of claim 28, wherein the physical connection is an insulator.

32. A method of oscillating switching, comprising:

a) providing an oscillating driven element;

b) selectively oscillating the driven element;

c) periodically contacting one or more switching contacts with the driven element, wherein, during contact, the oscillating driven element and the contacts form an electrically conductive path.

33. The method of claim 32, wherein the oscillating step comprises oscillating in a wine-glass mode.

34. The method of claim 32, wherein the selectively oscillating step comprises:

a) applying one sinusoidal voltage to two drive electrodes to achieve periodic contacting of the switching contacts with the driven element;

b) wherein the switch is periodically “

on”

.

35. The method of claim 32, wherein the selectively oscillating step comprises:

a) applying differential sinusoidal voltages to two drive electrodes to prevent periodic contacting of the switching contacts with the driven element;

b) wherein the switch is “

off”

.

36. The method of claim 32, comprising:

a) providing a second driven element vibrationally connected to the driven element;

b) applying a voltage to the drive electrodes of both the driven element and the second driven element;

c) thereby broadening the bandwidth of the oscillating switch.