1.14-GHz self-aligned vibrating micromechanical disk resonator

Micromechanical radial-contour mode disk resonators featuring new self-aligned stems have been demonstrated with record resonance frequencies up to 1.14 GHz and measured Q´s at this frequency >1,500 in both vacuum and air. In addition, a 733-MHz version has been demonstrated with Q´s of 7,330 and 6,100 in vacuum and air, respectively. For these resonators, self-alignment of the stem to exactly the center of the disk it supports allows balancing of the resonator far superior to that achieved by previous versions (where separate masks were used to define the disk and stem), allowing the present devices to retain high Q while achieving frequencies in the GHz range for the first time. In addition to providing measured results, this paper formulates an equivalent electrical circuit model that accurately predicts the performance of this disk resonator.