摘要 |
A tunable Q resonator using a capacitive-piezoelectric transducer provides a flexible top electrode above an AlN resonator. The top electrode can be pulled electrostatically towards the resonator and substrate, forming a frictional contact with either the resonator or the combined resonator-electrode structure to the substrate, allowing for electrical tuning the Q of the resonator. With a sufficient electrostatic bias voltage Vb, the resonator may be completely turned OFF, allowing for an integrated switchable AlN resonator. Such switchable resonator may be integrated into a radio frequency (RF) front end as a digitally selectable band pass filter element, obviating the need for ancillary micromechanical switches in the signal path. The device has been demonstrated with a Q approaching 9,000, together with ON/OFF switchability and electromechanical coupling up to 0.63%. Flexible positioning of the top electrode allows for actively controlling the series resonant frequency of the resonator through changes in capacitive coupling. |