Oscillator Apparatus

• US 20110057734A1
• Filed: 12/28/2009
• Published: 03/10/2011
• Est. Priority Date: 09/10/2009
• Status: Active Grant

• Current Assignee: RPX Corporation
• Original Assignee: Nokia Corporation
• Inventors: KIVIOJA, Jani, WHITE, Richard
• Granted Patent: US 8,084,336 B2
• Time in Patent Office: Days
• US Class Current: 331/56
• CPC Class Codes: H03B 5/30 with frequency-determining element being electromechanical resonator
• CPC Class Codes: Y10S 977/70 Nanostructure

Abstract

An apparatus including a resonator electrode and a second electrode separated from the resonator electrode by a gap having a size that facilitates electron transfer across the gap, wherein the resonator electrode is a resonator electrode mounted for oscillatory motion relative to the second electrode that results in a size of the gap between the resonator electrode and the second electrode being time variable; a feedback circuit configured to convey an electron transfer signal dependent upon electron transfer across the gap as a feedback signal; and a drive electrode adjacent the resonator electrode configured to receive a feedback signal from a feedback circuit configured to provide a time-varying feedback signal dependent upon electron transfer across a gap.

Claims

1. An apparatus comprising:

a resonator electrode and a second electrode separated from the resonator electrode by a gap having a size configured to facilitate electron transfer across the gap, wherein the resonator electrode is mounted for oscillatory motion relative to the second electrode that results in a size of the gap between the resonator electrode and the second electrode being time variable;

a feedback circuit configured to convey an electron transfer signal dependent upon electron transfer across the gap as a feedback signal; and

a drive electrode, for driving the resonator electrode, configured to receive a feedback signal from a feedback circuit that is configured to provide a feedback signal dependent upon electron transfer across a gap.

2. An apparatus as claimed in claim 1, further comprising an electrical energy source for providing a constant bias voltage which is used to develop a voltage across the gap.

3. An apparatus as claimed in claim 1, wherein the feedback circuit provides internal feedback that is at the same size scale as the resonator electrode.

4. An apparatus as claimed in claim 1, wherein the resonator electrode is a cantilever.

5. An apparatus as claimed in claim 1, wherein the apparatus is a nanoelectromechanical system and the resonator electrode is a nanostructure.

6. An apparatus as claimed in claim 1, wherein the drive electrode is sized and positioned so that the capacitance between the drive electrode and the resonator electrode enables self-sustaining oscillatory motion of the resonator electrode.

7. An apparatus as claimed in claim 1, wherein, in use, a probability of electron transfer across gap is dependent on a size of the gap, electron transfer across a time varying gap produces a time varying feedback signal, and a time varying feedback signal applied to the drive electrode provides a time varying field through which the resonator electrode moves.

8. An apparatus as claimed in claim 1, wherein the drive electrode adjacent the resonator electrode is configured to receive the feedback signal from the feedback circuit.

9. An apparatus as claimed in claim 1 comprising a plurality of oscillators where each oscillator comprises:

a resonator electrode and a second electrode separated from the resonator electrode by a gap having a size configured to facilitate electron transfer across the gap, wherein the resonator electrode is mounted for oscillatory motion relative to the second electrode that results in a size of the gap between the resonator electrode and the second electrode being time variable;

a feedback circuit configured to convey an electron transfer signal dependent upon electron transfer across the gap as a feedback signal; and

at least one drive electrode, for driving the resonator electrode, configured to receive a feedback signal from a feedback circuit that is configured to provide a feedback signal dependent upon electron transfer across a gap.

10. An apparatus as claimed in claim 9, wherein a common drive electrode is used for some or all of the plurality of oscillators.

11. An apparatus as claimed in claim 9, wherein a common second electrode is used for some or all of the plurality of oscillators.

12. An apparatus as claimed in claim 9, wherein the drive electrode of a first oscillator is configured to receive a feedback signal from the feedback circuit of a second oscillator.

13. An apparatus as claimed in claim 12, wherein the drive electrode of the first oscillator is configured not to receive a feedback signal from the feedback circuit of the first oscillator.

14. An apparatus as claimed in claim 9, further comprising a control mechanism configured to select which drive electrodes receive feedback signals from which oscillators.

15. An apparatus as claimed in claim 9, further comprising a control mechanism configured to selectively connect a drive electrode of a first oscillator to receive a selected feedback signal from anyone of a plurality of oscillators.

16. An apparatus as claimed in claim 9, further comprising a control mechanism configured to combine feedback signals of a selected plurality of oscillators to produce a combined feedback signal for one or more drive electrodes.

17. An apparatus comprising:

a resonator electrode and a second electrode configured such that first relative motion of the resonator electrode and the second electrode vary a gap between the resonator electrode and the second electrode;

means for conveying an electron transfer signal dependent upon electron transfer across the gap;

means for maintaining that a probability of electron transfer across the non-conductive gap is dependent on a distance across the gap;

means for changing a field through which the resonator electrode moves in dependence upon an electron transfer signal.

18. A method comprising:

conveying an oscillatory electron transfer current that is dependent upon electron transfer across a gap between a first oscillating electrode and a second electrode; and

driving the first oscillating electrode using an oscillatory electron transfer current that is dependent upon electron transfer across a gap between a third oscillating electrode and a fourth electrode

19. A method as claimed in claim 18, wherein first and third electrodes are the same electrode.

20. A method as claimed in claim 18, wherein first and third electrodes are different electrodes.

21. A method comprising:

depositing first material in nanoscale channels of a template;

depositing a nanoscale layer of a second material, different to the first material, in the nanoscale channels over the first material;

depositing third material in the nanoscale channels over the second material;

removing the template; and

removing the nanoscale layer of second material.

22. A method as claimed in claim 21, wherein the template is removed by an etch and the nanoscale layer of second material is removed by a different etch.

23. A method as claimed in claim 21, further comprising applying the template to a surface of a substrate before depositing first material in nanoscale channels of the template.

24. A method as claimed in claim 23, wherein the substrate is epitaxial semiconductor.

25. A method as claimed in claim 21, wherein the template is anodic aluminum oxide.

26. A method as claimed in claim 21, wherein the channels have a cross-sectional area that is substantially normal to their longest dimension and the cross-sectional area has a maximum span that is less than 100 nm

27. A method as claimed in claim 21, wherein the channels are open-ended and extend through the template to a substrate.

28. A method as claimed in claim 21, wherein the first material is a semiconductor in epitaxial registration with a substrate supporting the template.

29. A method as claimed in claim 21, wherein the first material is a single crystalline material.

30. A method as claimed in claim 21, wherein the first material is a semiconductor or a doped semiconductor.

31. A method as claimed in claim 21, wherein depositing first material in nanoscale channels of a template uses vapor-liquid-solid growth of a semiconductor.

32. A method as claimed in claim 21, wherein the nanoscale layer of second material is a sacrificial layer.

33. A method as claimed in claim 21, wherein the second material is conductive.

34. A method as claimed in claim 21, wherein the nanoscale layer is deposited using atomic layer deposition.

35. A method as claimed in claim 21, wherein the thickness of the second material is less than 10 nm.

36. A method as claimed in claim 21, wherein the thickness of the second material is controlled to a tolerance of less than 1 nm.

37. A method as claimed in of claim 21, wherein the third material is deposited using either vapor-liquid-solid growth or electro-deposition.

38. A method as claimed in of claim 21, further comprising depositing the third material so that it extends beyond the channels and forms a continuous layer connected to multiple channels.