Frequency compensated oscillator design for process tolerances

• US 20050073078A1
• Filed: 10/03/2003
• Published: 04/07/2005
• Est. Priority Date: 10/03/2003
• Status: Abandoned Application

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Partridge, Aaron, Lutz, Markus
• Application Number:
  US10/679,115
• Publication Number:
  US 20050073078A1
• Time in Patent Office: Days
• US Class Current: 267/136
• CPC Class Codes: H03H 2009/02299 Comb-like, i.e. the beam comprising a plurality of fingers or protrusions along its length
• CPC Class Codes: H03H 2009/0233 comprising perforations
• CPC Class Codes: H03H 2009/02496 Horizontal, i.e. parallel to the substrate plane
• CPC Class Codes: H03H 3/0072 of microelectro-mechanical resonators or networks micromembranes or microbeams B81B2203/01; manufacture of microstructural devices in general B81C
• CPC Class Codes: H03H 3/0076 for obtaining desired frequency or temperature coefficients
• CPC Class Codes: H03H 3/0077 by tuning of resonance frequency
• CPC Class Codes: H03H 9/2447 Beam resonators H03H9/2468 takes precedence
• CPC Class Codes: H03H 9/2457 Clamped-free beam resonators
• CPC Class Codes: H03H 9/2463 Clamped-clamped beam resonators
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making

Abstract

A continuous or distributed resonator geometry is defined such that the fabrication process used to form a spring mechanism also forms an effective mass of the resonator structure. Proportional design of the spring mechanism and/or mass element geometries in relation to the fabrication process allows for compensation of process-tolerance-induced fabrication variances. As a result, a resonator having increased frequency accuracy is achieved.

Claims

1-26. -26. (canceled).

27. A resonator comprising:

a spring-mass mechanism, having an effective mechanical stiffness and an effective mechanical mass defined by a geometry;

wherein the geometry and the effective mass of the spring-mass mechanism are simultaneously defined by application of a fabrication process to a constituent material; and

wherein the geometry is defined such that application of the fabrication process to the constituent material results in little change to a ratio defined by a change in the effective mechanical stiffness and a change in the effective mechanical mass.

28. The resonator of claim 27 wherein the geometry of the spring-mass mechanism comprises one or more voids formed in the length of the spring-mass mechanism.

29. The resonator of claim 27 wherein the geometry of the spring-mass mechanism comprises an outer edge having a plurality of indentations, the plurality of indentations having the effect of increasing a surface area of the outer edge exposed to the fabrication process.

30. The resonator of claim 27 wherein the spring-mass mechanism includes at least one mass structure that is formed integral to the spring-mass mechanism.

31. The resonator of claim 30 wherein at least one of the mass structure comprises one or more voids formed in a body of the at least one mass structure.

32. The resonator of claim 30 wherein at least one of the mass structure comprises an outer edge having a plurality of indentations, the plurality of indentations having the effect of increasing a surface area of the outer edge exposed to the fabrication process.

33. The resonator of claim 32 wherein the at least one of the mass structure further comprises one or more voids formed respectively in a body of the at least one of the mass structure.

34. The resonator of claim 27 wherein the spring-mass mechanism includes a plurality of mass structures that are formed integral to the spring-mass mechanism.

35. The resonator of claim 34 wherein each of the plurality of mass structures includes one or more voids formed in a body of the mass structure.

36. The resonator of claim 34 wherein each of the plurality of mass structures includes an outer edge having a plurality of indentations, wherein the plurality of indentations having the effect of increasing a surface area of the outer edge exposed to the fabrication process.

37. The resonator of claim 36 wherein each of the plurality of mass structures further includes one or more voids formed in a body of the mass structure.

38. The resonator of claim 27 wherein the spring-mass mechanism includes a plurality of spring structures that are formed integral to the spring-mass mechanism.

39. The resonator of claim 38 wherein each of the plurality of spring structures includes one or more voids formed in a body of the spring structure.

40. The resonator of claim 38 wherein each of the plurality of spring structures includes an outer edge having a plurality of indentations, and wherein the plurality of indentations having the effect of increasing a surface area of the outer edge exposed to the fabrication process.