Ring waveguide resonator on surface acoustic waves: First experiments

First results of numerical and physical experiments for the ring waveguide resonator on surface acoustic waves are presented. The structure consists of a gold interdigital transducer in the form of a ring placed on the $Z$ cut of aluminum nitride crystal. Excitation of radial modes is investigated. The electrical admittance frequency dependence of such resonator does not have sidelobes. A high quality factor is achievable.