Patent ID: 6831531
Filing Date: 2004-12-14
Classification: H03H

Abstract:
Time base comprising a resonator (4) and an integrated electronic circuit (3) for driving said resonator (4) into oscillation and for producing, in response to said oscillation, a signal having a determined frequency, characterised in that said resonator is an integrated micromechanical tuning fork resonator (4) supported above a substrate (2) and adapted to oscillate, according to a first oscillation mode, in a plane substantially parallel to said substrate (2), said tuning fork resonator (4) comprising:a base member (5) extending substantially perpendicularly from said substrate (2); a free-standing oscillating structure (6) connected to said base member (5) and including at least a first pair of substantially parallel fork tines (7, 8) disposed in said plane; and an electrode structure (9) disposed adjacent to said fork tines (7, 8) and connected to said integrated electronic circuit (3), said time base being further characterised in that each of said fork tines (7, 8) is provided with a comb-shaped structure (71, 81) disposed in said plane and including first electrode members (72, 82) extending substantially perpendicularly from a first side of said fork tines (7, 8), and in that said electrode structure (9) comprises at least one comb-shaped electrode structure (91, 92) meshing with said comb-shaped structure (71, 81) of a fork tine (7, 8) and comprising second electrode members (93, 94) adjacent to said first electrode members (72, 82).