A resonator includes an anchor, an outer stiffener ring on an outer perimeter of the resonator, and a plurality of curved springs between the anchor and the outer stiffener ring.

A resonant member of a MEMS resonator oscillates in a mechanical resonance mode that produces non-uniform regional stresses such that a first level of mechanical stress in a first region of the resonant member is higher than a second level of mechanical stress in a second region of the resonant member. A plurality of openings within a surface of the resonant member are disposed more densely within the first region than the second region and at least partly filled with a compensating material that reduces temperature dependence of the resonant frequency corresponding to the mechanical resonance mode.

A microelectromechanical resonator includes a support structure, a resonator element suspended to the support structure, and an actuator for exciting the resonator element to a resonance mode. The resonator element includes a plurality of adjacent sub-elements each having a length and a width and a length-to-width aspect ratio of higher than 1 and being adapted to a resonate in a length-extensional, torsional or flexural resonance mode. Further, each of the sub-elements is coupled to at least one other sub-element by one or more connection elements coupled to non-nodal points of the of said resonance modes of the sub-elements for exciting the resonator element into a collective resonance mode.

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.

A resonator is provided that includes a vibrating section that vibrates in a contour vibration mode, a frame that surrounds at least a portion of the vibrating section, supporting sections extending along a Y-axis direction and connecting the vibrating section and the frame. The vibrating section includes a through hole that extends along an X-axis direction perpendicular to the Y-axis direction such that a coupling section is disposed between the through hole and each of the supporting sections. The length SL of the through hole in the X-axis direction is longer than the length Sd of the coupling section in the Y-axis direction.

A microelectromechanical resonator includes a support structure, a resonator element suspended to the support structure, and an actuator for exciting the resonator element to a resonance mode. The resonator element includes a plurality of adjacent sub-elements each having a length and a width and a length-to-width aspect ratio of higher than 1 and being adapted to a resonate in a length-extensional, torsional or flexural resonance mode. Further, each of the sub-elements is coupled to at least one other sub-element by one or more connection elements coupled to non-nodal points of the of said resonance modes of the sub-elements for exciting the resonator element into a collective resonance mode.

A microelectromechanical (MEMS) resonator includes a spring-mass system having a first weight portion (M1), a second weight portion (M2), and a central spring portion (SP) in between the weight portions.

A microelectromechanical resonator assembly includes a first rectangular resonator array and a second rectangular resonator array, where the first rectangular resonator array and the second rectangular resonator array each have at least two rectangular resonator sub-elements, and the at least two rectangular resonator sub-elements are coupled to each other by one or more connection elements, and the first rectangular resonator array and the second rectangular resonator array are coupled to each other by one or more connection elements.

Devices and processes for preparing devices are described for reducing resonance of spurious waves in a bulk acoustic resonator and/or for obstructing propagation of lateral waves out of an active region of the bulk acoustic resonator. A first electrode is coupled to a first side of a piezoelectric layer and a second electrode is coupled to a second side of the piezoelectric layer to form a stack having the active region. The piezoelectric layer in the active region is configured to resonate in response to an electrical signal applied between the first electrode and the second electrode. One or more perforations in the first electrode, the piezoelectric layer and/or the second electrode, and/or one or more posts or beams supporting the stack, reduce resonance of spurious waves and obstruct propagation of lateral acoustic waves out of the active region.

A resonant member of a MEMS resonator oscillates in a mechanical resonance mode that produces non-uniform regional stresses such that a first level of mechanical stress in a first region of the resonant member is higher than a second level of mechanical stress in a second region of the resonant member. A plurality of openings within a surface of the resonant member are disposed more densely within the first region than the second region and at least partly filled with a compensating material that reduces temperature dependence of the resonant frequency corresponding to the mechanical resonance mode.