Patent ID: 6859113

Claim:
A time base comprising a resonator and an integrated electronic circuit for driving said resonator into oscillation and for producing, in response to said oscillation, a signal having a determined frequency, said resonator being an integrated micromechanical ring resonator supported above a substrate and adapted to oscillate, according to a first oscillation mode, around an axis of rotation substantially perpendicular to said substrate, said ring resonator comprising: a central post extending from said substrate along said axis of rotation; a free-standing oscillating structure connected to said central post and including an outer ring coaxial with said axis of rotation and connected to said central post by means of a plurality of spring elements; and electrodes disposed around said outer ring and connected to said integrated electronic circuit, wherein said electrodes are positioned under said free-standing oscillating structure in such a way as to drive and sense a second oscillation mode in a plane substantially perpendicular to said substrate and having a resonant frequency which is different from the resonant frequency of said first oscillation mode, a frequency difference between the resonant frequencies of both oscillation modes being used for compensating for the effect of temperature on the frequency of the signal produced by said time base.