Describe is a resonator that uses ferroelectric (FE) material in a capacitive structure. The resonator includes a first plurality of metal lines extending in a first direction; an array of capacitors comprising ferroelectric material; a second plurality of metal lines extending in the first direction, wherein the array of capacitors is coupled between the first and second plurality of metal lines; and a circuitry to switch polarization of at least one capacitor of the array of capacitors. The switching of polarization regenerates acoustic waves. In some embodiments, the acoustic mode of the resonator is isolated using phononic gratings all around the resonator using metal lines above and adjacent to the FE based capacitors.