An ultrasonic transducer positionable in a wellbore environment may include a piezoelectric material layer, a protective layer, and connecting plate positioned between the piezoelectric material layer and the protective layer. The piezoelectric material layer may be formed as a plurality of columns of piezoelectric material for detecting a characteristic of the wellbore environment during a drilling operation. The protective layer may be positionable between the piezoelectric material layer and an acoustic medium in the wellbore environment. The connecting plate may be positioned between the piezoelectric material layer and the protective layer. The connecting plate may have a coefficient of thermal expansion (CTE) in a range between the CTE of the piezoelectric material layer and that of the protective layer, and an acoustic impedance in a range between the acoustic impedance of the piezoelectric material layer and that of the protective layer.

Described are transducer assemblies and imaging devices comprising: a microelectromechanical systems (MEMS) die including a plurality of piezoelectric elements; a complementary metal-oxide-semiconductor (CMOS) die electrically coupled to the MEMS die by a first plurality of bumps and including at least one circuit for controlling the plurality of piezoelectric elements; and a package secured to the CMOS die by an adhesive layer and electrically connected to the CMOS die.

Aspects of this disclosure relate to driving a capacitive micromachined ultrasonic transducer (CMUT) with a pulse train of unipolar pulses. The CMUT may be electrically excited with a pulse train of unipolar pulses such that the CMUT operates in a continuous wave mode. In some embodiments, the CMUT may have a contoured electrode.

A device for supplying an ultrasonic transducer including a power interface configured to provide an analog power signal, called supply signal, to the ultrasonic transducer, and further including a delta-sigma modulator configured to produce a delta-sigma modulator of a sinusoidal signal, called drive signal, and provide a digital signal, called control signal, to control said power interface. Also an ultrasonic device powered by such a supply device, an ultrasonic head including such ultrasonic devices and an ultrasonic system including such an ultrasonic head.

A circuit of control of ultrasound transducers, is configurable according to the type of transducers to be controlled, and includes a first terminal intended to be coupled to a first electrode of each of the transducers, and a bias switch configurable to couple the first terminal to one or the other of first and second bias nodes according to the type of transducers to be controlled.

Systems and methods are disclosed for improving broad bandwidth performance of CMUT elements and arrays using negative capacitance-based impedance matching. The disclosed systems and methods provide a controllable compromise balance between electrical power transfer, acoustic reflectivity, and signal-to-noise ratio. Certain implementations utilize active control of impedance network parameters based on a DC bias input to the CMUT. Instead of minimizing electrical reflection, acoustic reflectivity is controlled to provide improved SNR-bandwidth. Negative capacitance-based matching is tunable to accommodate collapsed mode CMUTs where capacitance and frequency response changes significantly with DC bias.

A multilayer ultrasonic transducer of an embodiment includes: a plurality of stacked oscillators; external electrodes disposed on outer exposed surfaces of two oscillators disposed in the outermost layers out of the plurality of oscillators; and a plurality of internal electrodes each disposed between two of the plurality of oscillators. There are provided electrode regions in which the plurality of internal electrodes are arranged such that the number of layers of the internal electrodes in a direction in which the oscillators are stacked gradiently increases from an inner region toward an outer peripheral region of the plurality of oscillators, and ultrasonic waves emitted from the plurality of oscillators are focused toward at least the inner region.

An ultrasonic device includes a driving circuit to provide drive power, a first transducer array to generate ultrasonic waves, the first transducer array being connected to receive power from the driving circuit, and a second transducer array to detect reflected or elicited ultrasonic waves incident on the device from a target and generate a signal based on those waves, the second transducer array being acoustically transmissive and disposed over the first transducer array such that the generated ultrasonic waves pass through the second transducer array. The second array is tuned to operate on top of the first. The functions of the two arrays may be reversed and the array tuned to operate with the first array receiving and the second array transmitting.

The invention relates to hydroacoustic domain, notably to methods and devices of active location. The method of controlling intercarrier frequency wave efficiency with parametric radiating antenna is based on placing electroacoustic transducer with piezoelement with given resonance frequency (f.sub.1+f.sub.2)/2=f.sub.0 and pass band corresponding to intercarrier frequency wave diapason in locating area, feeding electric signals from radiating tract output to electroacoustic transducer piezoelement, forming in locating area spatial area of collinear distribution and non-linear interaction of intense ultrasound pimp waves, generation of intercarrier frequency wave with cyclic frequency Ω=2π|f.sub.1−f.sub.2|. New features are the following: multicomponent excitation signal if formed due to generating in radiating tract N oscillations with similar amplitude and with similar initial phase at the period of time t=0), with frequencies ω.sub.v, sequentially differing from each other by Ω=2πF_ and situated in pass band of piezoelement and coming from radiating tract output to piezoelement with resonance cyclic frequency ω.sub.0=2πf.sub.0 electric multicomponent signal of escitation, presented as sum of N oscillations and regulation of generation efficiency and adjusting of field parameters (N−1) of intercarrier frequency component wave with cyclical frequencies Ω, 2Ω, . . . , (N−1)Ω formed by parametric radiating antenna, implemented by switching off of antiphase switching on of given constituents set. The method is implemented due to the device that includes reference generator, delayed pulse-shaping circuit, (N−1) coincidence circuit, N frequency dividers, analog switch, adder, amplitude modulator, impulse generator, power amplifier, electroacoustic transducer, controlling and adjustment unit.

An electronic device includes a load, a first switching element, a drive circuit, and a second switching element. The first switching element is disposed on a current path connected to the load. The drive circuit drives the first switching element by using a drive control signal which is based on a comparison result between a load signal and a reference signal. The load signal is obtained by converting, into a voltage, a current flowing through the current path. The reference signal serves as a reference of an operation of the first switching element. The second switching element is capable of switching the signal level of the drive control signal between a first level, at which the first switching element is switched off, and a second level, at which the first switching element is switched on.