MEMS ultrasonic transducer, MUT, device, comprising a semiconductor body with a first and a second main face, including: a modulation cavity extending into the semiconductor body from the second main face; a membrane body suspended on the modulation cavity and comprising a transduction membrane body and a modulation membrane body; a piezoelectric modulation structure on the modulation membrane body; a transduction cavity extending into the membrane body, the transduction membrane body being suspended on the transduction cavity; and a piezoelectric transduction structure on the transduction membrane body. The modulation membrane body has a first thickness and the transduction membrane body has a second thickness smaller than the first thickness. In use, the modulation membrane vibrates at a first frequency and the transduction membrane vibrates at a second frequency higher than the first frequency, to emit and/or receive acoustic waves at a frequency dependent on the first and the second frequencies.

A survey system including a transmitter, receiver, projector array and hydrophone array transmits and receives sound waves to perform one or more survey missions.

A survey system including a transmitter, receiver, projector array and hydrophone array transmits and receives sound waves to perform one or more survey missions.

The disclosure provides an ultrasonic signal detection circuit including a sensing circuit, a unidirectional conduction circuit and a source follower circuit. The sensing circuit is connected to an input terminal of the source follower circuit through the unidirectional conduction circuit; the sensing circuit is configured to generate a piezoelectric signal according to a received ultrasonic echo signal and output the piezoelectric signal to the unidirectional conduction circuit. The piezoelectric signal is an alternating current signal; the unidirectional conduction circuit is configured to rectify the alternating current signal to only allow a forward or a reverse current portion thereof to pass through. The forward/reverse current portion charges/discharges the input terminal of the source follower circuit after passing through the unidirectional conduction circuit. The source follower circuit is configured to generate a detection signal according to a voltage at its input terminal and output the detection signal through its output terminal.

The disclosure provides an ultrasonic signal detection circuit including a sensing circuit, a unidirectional conduction circuit and a source follower circuit. The sensing circuit is connected to an input terminal of the source follower circuit through the unidirectional conduction circuit; the sensing circuit is configured to generate a piezoelectric signal according to a received ultrasonic echo signal and output the piezoelectric signal to the unidirectional conduction circuit. The piezoelectric signal is an alternating current signal; the unidirectional conduction circuit is configured to rectify the alternating current signal to only allow a forward or a reverse current portion thereof to pass through. The forward/reverse current portion charges/discharges the input terminal of the source follower circuit after passing through the unidirectional conduction circuit. The source follower circuit is configured to generate a detection signal according to a voltage at its input terminal and output the detection signal through its output terminal.

Multiplexed phased array sonar systems and methods for consumer fishfinders are described herein. In one embodiment a single curved transmit transducer and an array of receive transducers are provided, and in an embodiment the signals from the receive transducers are multiplexed, which greatly reduces the data load, allowing for the achievement of the near real time, high resolution imagery in a size and price point that enables this technology to be employed in a consumer fish finder.

Multiplexed phased array sonar systems and methods for consumer fishfinders are described herein. In one embodiment a single curved transmit transducer and an array of receive transducers are provided, and in an embodiment the signals from the receive transducers are multiplexed, which greatly reduces the data load, allowing for the achievement of the near real time, high resolution imagery in a size and price point that enables this technology to be employed in a consumer fish finder.

An air-coupled ultrasonic interferometric method is disclosed. An air-coupled ultrasonic transducer, as a probe, is placed directly facing the surface of a workpiece, and an ultrasonic wave is reflected back and forth between the ultrasonic transducer and the surface of the workpiece; the phase difference of the first echo reflected from the surface of the workpiece and reaching the air-coupled ultrasonic transducer is measured; based on the change of the ultrasonic frequency and wavelength, the measured distance is transformed into the rate of change of the acoustic phase with respect to the acoustic angular frequency, wherein the change in the acoustic angular frequency is a product obtained by multiplying 2 by the difference between the highest frequency F2 and the lowest frequency F1 within the bandwidth fB of the air-coupled ultrasonic transducer.

A method includes configuring a transmitter to provide at least three output levels used to form an output signal. The method further includes adjusting a duration of at least one of the output levels to control an average value of the output signal independently of an amplitude of a first harmonic of the output signal.

A sound wave processing device includes a transmission signal generation unit that generates a transmission signal for transmitting a sound wave, a received wave signal output unit that outputs a received wave signal based on receiving the sound wave, a correlation-convolution integral processing unit that performs correlation-convolution integral processing in parallel for each reference wave data, on the basis of the received wave signal and a plurality of reference wave data, and an own wave identification unit that determines whether or not the received sound wave is own wave, which is a reflected wave of the sound wave transmitted by the transmission signal generation unit, on the basis of a correlation-convolution integral value output from the correlation-convolution integral processing unit.