Absolute calibration of membrane hydrophones up to 40 MHz in ultrasonic far-field

A 1 mm radius plane P(VDF-TrFE) transducer was designed and developed to calibrate hydrophone at high frequencies in far-field using a optical method. The transducer features a wide frequency range and a small effective radius. A membrane hydrophone was calibrated using the transducer in the frequency range from 10 MHz to 40 MHz in far-field with a 1 MHz frequency interval. The differences of the calibration results using the transducer and our current system were within 3 % in the frequency range from 10 MHz to 20 MHz.