Multilayer piezoelectric substrate device with negative temperature coefficient of frequency dielectric film for temperature stability

A radio frequency module comprising:

• a package substrate;
• an acoustic wave filter configured to filter a radio frequency signal, the acoustic wave filter including a piezoelectric layer over a substrate, a first plurality of acoustic wave resonators disposed over the piezoelectric layer arranged in series along a first branch, a second plurality of acoustic wave resonators disposed over the piezoelectric layer and arranged in parallel with the first plurality of acoustic wave resonators, and a layer of negative temperature coefficient of frequency dielectric material disposed over at least a first acoustic wave resonator of the second plurality of acoustic wave resonators and not disposed over at least a second acoustic wave resonator of the second plurality of acoustic wave resonators;
• and
• additional circuitry, the acoustic wave filter and additional circuitry disposed on the package substrate.