Describe is a resonator that uses ferroelectric (FE) materials in the gate of a transistor as a dielectric. The use of FE increases the strain/stress generated in the gate of the FinFET. Along with the usual capacitive drive, which is boosted with the increased polarization, FE material expands or contacts depending on the applied electric field on the gate of the transistor. As such, acoustic waves are generated by switching polarization of the FE materials. In some embodiments, the acoustic mode of the resonator is isolated using phononic gratings all around the resonator using the metal line above and vias' to body and dummy fins on the side. As such, a Bragg reflector is formed above the FE based transistor.