Piezoelectric transducer for ultrasonic waves - has transducer with polymeric piezoelectric element of higher acoustic impedance than reflector and half wavelength thickness

Abstract

Abstract This piezoelectric transducer is intended to transmit or receive ultrasonic waves in a medium (6) whose acoustic impedance is similar to that of water, and can be used, for example, in the medical examinations using echography methods. The piezoelectric transducer has a large bandwidth, and contains a piezoelectric polymer active component (1) inserted between two electrodes (4a,4b) which form a capacitor. The active component (1) is excited in a transverse vibration mode. One of its faces (1a) is coupled to the medium (6) which receives or transmits ultrasonic waves. Its other face (1b) is coupled to a reflective medium (30). The impedance of the reflective medium (30) is appreciably lower than the impedance of the piezoelectric polymer (1). The active component (1) thickness is half a wavelength at the centre frequency of the transducer.

Inventors

• 👤 Nguyen Hoang Giang

Bibliographic Details