Design dependent transition behavior for superconducting transducers and reflectors

High transition temperature superconducting YBa/sub 2/Cu/sub 3/O/sub 7-/spl delta// (YBCO) SAW transducers have been theoretically and experimentally proven to exhibit a change in insertion loss as the transducers become superconducting. Previous devices were designed for center frequencies of 50 MHz. Such devices were shown to decrease in insertion loss as the samples descended below the transition temperature of the transducers. The amount of change for a 100 MHz device is not different from a 50 MHz device if the devices have the same beamwidth. In this study such dependence is experimentally verified by showing that the transition temperature change in insertion loss follows the theoretical prediction when the transducers have different beamwidth. Transition temperature reflectivity variation of a high T/sub c/ array is also presented.