Acoustic wave resonator RF filter circuit and system

An RF filter system, comprising:

• a plurality of bulk acoustic wave resonators arranged in a circuit, the circuit including a serial configuration of resonators and a parallel shunt configuration of resonators, the circuit having a circuit response corresponding to the serial configuration and the parallel configuration of the plurality of bulk acoustic wave resonators, each of the resonators of the plurality of resonators comprising:
• a support member including a surface, the support member including a multilayer reflector structure including two pairs of a low impedance material layer and a high impedance material layer when the material layers are compared to each other;
• a first electrode including tungsten overlying the multilayer reflector structure;
• a piezoelectric film including aluminum scandium nitride overlapping the first electrode and overlying the multilayer reflector structure;
• a second electrode including tungsten overlapping the piezoelectric film, overlapping the first electrode, and overlying the multilayer reflector, a resonator area being defined by an area where the second electrode, the piezoelectric film, and the first electrode overlap;
• a passivation layer including silicon nitride overlying the second electrode;
• wherein,
• portions of the surface of the support member of at least one resonator of the plurality of bulk acoustic wave resonators define a cavity region and at least a portion of the first electrode of the at least one resonator is located within the cavity region defined by the surface of the support member;
• and
• the circuit response corresponding to the serial configuration and the parallel configuration of the plurality of resonators has a pass band having a bandwidth from 5.490 GHz to 5.835 GHz;
• at least one resonator of the plurality of bulk acoustic wave resonators includes at least one trimmed material layer such that the pass band of the circuit has a bandwidth from 5.490 to 5.835 GHz, wherein the at least one trimmed material layer includes a first thickness in the resonator area that is thinner than a second thickness in another area of the same material layer such that the pass band of the circuit has a bandwidth from about 5.490 to 5.835 GHz.