Time base comprising an integrated micromechanical tuning fork resonator

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).