MODULATION IN MICROMACHINED ULTRASONIC TRANSDUCERS

摘要

A capacitive micromachined ultrasonic transducer (cMUT) system uses a modulation technique to increase cMUT sensitivity. An AC carrier signal is applied to the cMUT through a modulation signal port to modulate the signal. The higher frequency of the AC carrier signal carries the real signal to a high frequency range to increase the output current signal level. The real signal is later recovered by demodulation. The technique is applicable in both the reception mode and the transmission mode.