Abstract: A fingerprint sensor is provided herein. A method for operating the fingerprint sensor can comprise selecting a pair of electrode elements from a first set of electrode elements and a second set of electrode elements of a second electrode. The first electrode is located on a first side of a piezoelectric layer; the second electrode is located on a second side of the piezoelectric layer. The first side and the second side are opposite sides of the piezoelectric layer. The method also can comprise transmitting ultrasonic signals using the pair of electrode elements based on a position of a switch element being in a first position, and receiving ultrasonic signals using the pair of electrode elements based on the position of the switch element being in a second position.