Direct Modulation Piezoelectric Micro-Machined Ultrasonic Transducer System (DMUT)

This paper demonstrates, for the first time, a new underwater communication scheme based on the Direct Modulation (DM) of an array of piezoelectric Micro-Machined Ultrasonic Transducers (MUT). The use of this new modulation scheme permits to achieve more efficient data transmission compared to what could be attained through conventional continuous waves-based (CW) driving approaches. In addition, as the received information can be extracted without the employment of mixers or amplifiers, it enables lower power consumption and low noise-figures. In this work, we report on the performance of the first dMUT-prototype. This system, which relies on a Bipolar Junction Transistor (BJT) to periodically connect and disconnect an array of pMUTs to a DC-biased filter (Fig. 1), exhibits power consumption of 140mW and enables transmitted energy-per-bit of 0.7μJ. Such a value is two orders-of-magnitude more efficient than what attained through conventional communication approaches for underwater networks [1]-[3].