Bulk acoustic wave resonator with patterned layer structures, devices and systems

A millimeter wave filter comprising a plurality of bulk acoustic millimeter wave resonators over a substrate, in which at least one bulk acoustic millimeter wave resonator of the plurality of bulk acoustic millimeter wave resonators includes at least:

• a first piezoelectric layer, a second piezoelectric layer, and a third piezoelectric layer having respective thicknesses to facilitate a main resonant frequency in a millimeter wave frequency band;
• an electrode electrically and acoustically coupled with the third piezoelectric layer;
• and
• a patterned layer associated with the electrode, in which the patterned layer is acoustically coupled with the third piezoelectric layer to facilitate a suppression of a spurious mode of the at least one bulk acoustic millimeter wave resonator.

A millimeter wave oscillator comprising:

• electrical oscillator circuitry;
• and
• a bulk acoustic millimeter wave resonator coupled with the electrical oscillator circuitry to excite electrical oscillation in the bulk acoustic millimeter wave resonator, in which the bulk acoustic millimeter wave resonator includes at least:
• a first piezoelectric layer, a second piezoelectric layer, and a third piezoelectric layer;
• an electrode electrically and acoustically coupled with the third piezoelectric layer to facilitate a main resonant frequency of the bulk acoustic millimeter wave resonator;
• and
• a patterned layer associated with the electrode, in which the patterned layer is acoustically coupled with the third piezoelectric layer to facilitate a suppression of a spurious mode of the bulk acoustic millimeter wave resonator.

An acoustic millimeter wave device comprising:

• a substrate;
• a first piezoelectric layer having a first piezoelectric axis orientation;
• a second piezoelectric layer having a second piezoelectric axis orientation;
• a third piezoelectric layer acoustically coupled with the second piezoelectric layer, the third piezoelectric layer having a third piezoelectric axis orientation that is antiparallel to the second piezoelectric axis orientation;
• a first electrode electrically interfacing with the third piezoelectric layer;
• and
• a patterned layer associated with the first electrode, in which the patterned layer is acoustically coupled with the third piezoelectric layer to facilitate a suppression of a spurious mode of the acoustic millimeter wave device.