Quality Factor Boosting via Mechanically-Coupled Arraying

A mechanical circuit-based approach for boosting the Q of a vibrating micromechanical resonator has been demonstrated whereby a low Q resonator is embedded into a mechanically-coupled array of much higher Q resonators to raise its functional Q by a factor approximately equal to the number of resonators in the array. Using this method, the low Q of 7,506 exhibited by a support-loss-limited 60- MHz wine-glass disk resonator by itself was effectively raised by about 9X to 63,207 when emp laced into a mechanically-coupled array of eight very high-g wine-glass disks that then form a composite resonator. The availability of such a circuit-based Q-enhancement technique has far reaching implications, especially considering the possibility of raising the functional Q of a piezoelectric resonator by merely mechanically coupling it to an array of much higher Q capacitively-transduced ones to simultaneously obtain the most attractive characteristics of both technologies: low impedance from the piezo-device and high-g from the capacitive ones. Furthermore, the methods of this work stand to enhance the manufacturing repeatability of micromechanical resonator-based products, since they present a convenient method for en suring g's greater than a specified threshold value, even when some resonator's Q's are lower than it.