Acoustic resonator in transverse excitation shear mode

A laterally excited shear mode acoustic resonator, comprising:

• an acoustic mirror comprising at least one first acoustic reflection layer and at least one second acoustic reflection layer, acoustic impedance of each first acoustic reflection layer being less than that of each second acoustic reflection layer;
• a piezoelectric layer disposed on the acoustic mirror and comprising monocrystalline lithium niobate and/or monocrystalline lithium tantalate;
• an electrode unit disposed on the piezoelectric layer and configured to form an electric field;
• and
• lateral reflectors disposed on the piezoelectric layer and configured to laterally reflect a sound wave;
• wherein
• electrode unit comprises:
• a first common electrode,
• a second common electrode,
• a plurality of first interdigitated electrodes, and
• a plurality of second interdigitated electrodes,
• the first interdigitated electrodes are electrically connected to the first common electrode, the second interdigitated electrodes are electrically connected to the second common electrode, the first interdigitated electrodes are insulated from the second interdigitated electrodes, the first common electrode is configured to receive an input voltage, and the second common electrode is configured to be grounded;
• and
• a direction of connection between the lateral reflectors on two sides of the electrode unit is a propagation direction of the sound wave;
• each of the first acoustic reflection layers and each of the second acoustic reflection layers of the acoustic mirror are aligned on two side edges of a first direction, the first direction is perpendicular to the direction of connection on a plane, and the plane is perpendicular to a height direction of the resonator;
• a first end of each of the first interdigitated electrodes is connected to the first common electrode, a first end of each of the second interdigitated electrodes is connected to the second common electrode, an orthographic projection of the first end of each of the first interdigitated electrodes on the acoustic mirror is aligned with a first side edge of the acoustic mirror in the first direction, and an orthographic projection of the first end of each of the second interdigitated electrodes on the acoustic mirror is aligned with a second side edge of the acoustic mirror in the first direction.