Acoustic wave devices with thermal bypass

An acoustic wave device comprising:

• a substrate that decreases in electrical resistivity in response to an increase in temperature;
• a piezoelectric layer over the substrate;
• and
• an interdigital transducer electrode, the piezoelectric layer disposed between the substrate and the interdigital transducer electrode, the interdigital transducer electrode including a first bus bar, second bus bar, a first plurality of fingers extending from the first bus bar toward the second bus bar, a second plurality of fingers extending towards the first bus bar, a first coupling portion on the first bus bar that extends through at least part of the piezoelectric layer towards the substrate to electrically couple the first bus bar to the substrate, and a second coupling portion on the second bus bar that extends through at least part of the piezoelectric layer towards the substrate to electrically couple the second bus bar to the substrate, the first and second coupling portions transfer electrical current from the first bus bar to the second bus bar through the substrate below the piezoelectric layer based at least in part on the temperature of the substrate.

A method of operating an acoustic wave device, the method comprising:

• transferring electrical current from a first bus bar to a second bus bar via a first pathway through interdigitated fingers of an interdigital transducer electrode on a piezoelectric layer that is disposed between a substrate and the interdigital transducer electrode, the substrate decreasing in electrical resistivity in response to increasing temperature;
• transferring electrical current from the first bus bar to the second bus bar via a second pathway through the substrate, the second pathway including a first coupling portion that extends from the first bus bar through the piezoelectric layer towards the substrate to electrically couple with the substrate, and the second pathway further including a second coupling portion that extends from the second bus bar through the piezoelectric layer towards the substrate to electrically couple with the substrate;
• and
• bypassing the first pathway with the second pathway based at least in part on temperature of the substrate.