Anchor loss reduction of quartz resonators utilizing phononic crystals

This study aims at developing an AT-cut quartz resonator with low anchor loss. Phononic crystals are utilized for trapping acoustic energy and reducing anchor loss of the AT-cut quartz resonators. Finite element analyses of the AT-cut quartz resonators with phononic crystals and the lossy epoxy attachments are presented herein. The resonance response of an AT-cut quartz resonator with no phononic crystal was first calculated. A square-lattice phononic crystal plate, made of an AT-cut quartz plate with air holes, was analyzed and designed to have a complete band gap covering the quartz resonator's resonance frequency. Finally, the mode shape and impedance of the quartz resonator with 3 rows of phononic crystals were calculated to evaluate the isolation performance of the phononic crystals. Results show the quartz resonator with the through-hole phononic crystals exhibits a good energy confinement inside electrode area and small impedance. Accordingly, the phononic crystal is verified to be capable of reducing anchor loss in an AT-cut quartz resonator.