FIG. 1A is a diagram illustrating a piezoelectric micromachined ultrasonic transducer (PMUT) device having a center pinned membrane, according to some embodiments.
FIG. 1B is a diagram illustrating a PMUT device having an unpinned membrane, according to some embodiments.
FIG. 2 is a diagram illustrating an example of membrane movement during activation of a PMUT device, according to some embodiments.
FIG. 3 illustrates an example array of square-shaped PMUT devices, according to some embodiments.
FIG. 4 illustrates an example fingerprint sensor, in accordance with various embodiments.
FIGS. 5A, 5B, and 5C illustrates cross section views of ultrasonic fingerprint sensors having contact layers of varying thicknesses, according to an embodiment.
FIG. 6A illustrates an example of interference pattern generation during image capture at an ultrasonic fingerprint sensor having a contact layer of varying thicknesses, according to an embodiment.
FIG. 6B illustrates an example interference pattern generated using one pulse of ultrasonic signals by an ultrasonic fingerprint sensor having a contact layer of varying thicknesses, according to an embodiment.
FIG. 6C illustrates an example interference pattern generated using three pulses of ultrasonic signals by an ultrasonic fingerprint sensor having a contact layer of varying thicknesses, according to an embodiment.
