Integrated resonator with a mass bias

A method of forming a piezoelectric resonator with a Bragg reflector, comprising:

• depositing alternating dielectric layers of lower and higher acoustic impedance materials over a substrate;
• depositing a first resonator electrode over the alternating dielectric layers;
• depositing a piezoelectric layer over the first resonator electrode;
• depositing a second resonator electrode over the piezoelectric layer;
• depositing a mass bias over the resonators;
• and
• encapsulating the mass bias, first and second electrodes, piezoelectric layer, and alternating dielectric layers with a plastic.