Transmission line model equivalent circuit for piezoelectric transducers including the effect of electrical terminal impedance

A new transmission line model equivalent circuit for a thickness-mode piezoelectric vibrator is derived. The equivalent circuit includes an electrical impedance connected to the terminals of a piezoelectric vibrator. A bolt-clamped frequency-controllable piezoelectric transducer is analyzed by using the equivalent circuit. The changes in particle velocity distribution by varying the electrical impedance in the frequency-controllable ultrasonic transducer are measured by a noncontact method based on laser Doppler velocimetry. The changes in particle velocity distribution agree well with results calculated using the new equivalent circuit.