RF Detection for Low Frequency cMUTS and its Comparison to Traditional Detection

Capacitive micromachined transducers have long been used as generators and detectors of ultrasound both in air and immersion applications [l-31. Typically, the frequency of operation has been in the MHz range. However, they can still be operated at very low frequencies, where their mechanical sensitivity is poor, but the frequency response is flat. In this paper we show that, together with the RF detection method that provides a very sensitive and broadband acoustic detection [4], [5], it is possible to operate the cMUTs at very low frequencies, which covers the microphone and sonar applications. Keywordsmicrophone, RF Detection, Capacitive Transducers.