Three-port piezoelectric ultrasonic transducer

An apparatus comprising:

• a piezoelectric micromechanical ultrasonic transducer (PMUT), the PMUT including:
• a diaphragm disposed over a cavity, the diaphragm including a piezoelectric layer stack including a piezoelectric layer, a first electrode electrically coupled with transceiver circuitry, and a second electrode electrically coupled with the transceiver circuitry, wherein:
• the first electrode is disposed in a first portion of the diaphragm, and the second electrode is disposed in a second portion of the diaphragm, the first portion being separated from the first portion;
• each of the first electrode and the second electrode is disposed on or proximate to a first surface of the piezoelectric layer, the first surface being opposite from the cavity;
• and
• the PMUT is configured to transmit first ultrasonic signals by way of the first electrode during a first time period and to receive second ultrasonic signals by way of the second electrode during a second time period, the first time period and the second time period being at least partially overlapping.

An apparatus comprising:

• an array of piezoelectric micromechanical ultrasonic transducer (PMUT) sensors;
• and
• an acoustic coupling medium, wherein:
• at least one PMUT includes a diaphragm disposed over a cavity, the diaphragm including a piezoelectric layer stack including a piezoelectric layer, a first electrode electrically coupled with a transceiver circuitry, and a second electrode electrically coupled with the transceiver circuitry;
• the first electrode is disposed in a first portion of the diaphragm, and the second electrode is disposed in a second portion of the diaphragm, the first portion being separated from the second portion;
• each of the first electrode and the second electrode is disposed on or proximate to a first surface of the piezoelectric layer, the first surface being opposite from the cavity;
• the PMUT is configured to transmit first ultrasonic signals by way of the first electrode during a first time period and to receive second ultrasonic signals by way of the second electrode during a second time period, the first time period and the second time period being at least partially overlapping;
• the acoustic coupling medium is disposed above the piezoelectric layer stack;
• and
• the PMUT is configured to receive or transmit ultrasonic signals through the acoustic coupling medium.