US Patent 9214623 Doped piezoelectric resonator

Mechanical resonators including doped piezoelectric active layers are described. The piezoelectric active layer(s) of the mechanical resonator may be doped with a dopant type and concentration suitable to increase the electromechanical coupling coefficient of the active layer. The increase in electromechanical coupling coefficient may all for improved performance and smaller size mechanical resonators than feasible without using the doping.