Acoustic wave device

An acoustic wave device comprising:

• a first piezoelectric layer and a second piezoelectric layer each made of lithium niobate or lithium tantalate and including a first principal surface and a second principal surface opposite to the first principal surface in a thickness direction;
• at least one pair of a first electrode and a second electrode on the first principal surface of the first piezoelectric layer and opposed to each other in a planar direction of the first principal surface;
• and
• at least one pair of a third electrode and a fourth electrode on the first principal surface of the second piezoelectric layer and opposed to each other in a planar direction of the first principal surface;
• wherein
• the first piezoelectric layer and the at least one pair of the first electrode and the second electrode define a first acoustic wave resonator;
• the second piezoelectric layer and the at least one pair of the third electrode and the fourth electrode define a second acoustic wave resonator;
• d/p is about 0.5 or less where an average thickness of each of the first piezoelectric layer and the second piezoelectric layer is denoted by d and center-to-center distances between the first electrode and the second electrode adjacent to each other and between the third electrode and the fourth electrode adjacent to each other are each denoted by p;
• and
• an angle between a crystal orientation of the first piezoelectric layer and a direction perpendicular or substantially perpendicular to a lengthwise direction of the at least one pair of the first electrode and the second electrode is different from an angle between a crystal orientation of the second piezoelectric layer and a direction perpendicular or substantially perpendicular to a lengthwise direction of the at least one pair of the third electrode and the fourth electrode.