Observations of novel acoustic waves in quartz.

A new design for a surface acousti wave resonator on quartz has been fabricated and tested. In place of the interdigital transducer electrode that is normally used to generate surface waves at a frequency determined by the pitch of the electrode fingers, a metallized piezo surface is fabricated with an oval opening in the metallization. A drive and a receiving electrode are placed within this opening. Surface waves launched from the drive electrode propagate through the open region and are quenched at the boundary of the outer metallized field. This geometry establishes conditions that support drumhead resonant modes within the device which are observed in the transmission and reflection properties of the device. Due to the geometry, these acoustic waves are inherently radial in nature and to the best of our knowledge have not been formally analyzed in the past.