High-quality-factor flexural-vibration resonator for producing time references force sensors or gyrometers

A resonator comprising:

• a portion of a wafer having two opposite faces which are flat and parallel, the wafer portion being intended to vibrate flexurally during use of the resonator, and referred to as the vibrating portion;
• and
• a support part, which is external to the vibrating portion and connected thereto by an intermediate segment of the wafer referred to as a foot, said foot being integral with the vibrating portion and forming a rigid connection between the support part and said vibrating portion,
• the vibrating portion having a first plane of symmetry, referred to as the midplane, which is parallel to both faces of the wafer and equidistant from said two faces, and a second plane of symmetry, referred to as the plane of symmetry orthogonal to the wafer, which is perpendicular to the midplane and which passes longitudinally through the connection formed by the foot between the support part and the vibrating portion,
• an intersection between the midplane and the plane of symmetry orthogonal to the wafer constituting a center axis of the vibrating portion,
• the vibrating portion comprising two extensions which are each intended to vibrate flexurally, said two extensions extending symmetrically from the foot on each side of the plane of symmetry orthogonal to the wafer,
• wherein each extension is provided with a longitudinal slot which passes through the vibrating portion perpendicularly to the midplane, from the plane of symmetry orthogonal to the wafer towards a distal end of said extension but without reaching said distal end, so that each extension is meander shaped, the respective slots of the two extensions being symmetrical relative to the plane of symmetry orthogonal to the wafer, and meeting at said plane of symmetry orthogonal to the wafer, so that the vibrating portion comprises two primary segments which each connect the foot to the distal end of one of the extensions, and two secondary segments which are interconnected at the plane of symmetry orthogonal to the wafer by respective proximal ends of said secondary segments, and which each extend to the distal end of one of the extensions so as to connect to one of the primary segments at said distal end,
• such that for a mode of vibration of the vibrating portion which comprises only movements parallel to the midplane, and which is symmetrical relative to the plane of symmetry orthogonal to the wafer, both primary segments have instantaneous velocity components, parallel to the center axis, which at each instant during vibration, are in the opposite direction to that of instantaneous velocity components of the secondary segments, also parallel to the center axis.