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.

Ultrasonic sensing approaches are described with integrated MEMS-CMOS implementations. Embodiments include ultrasonic sensor arrays for which PMUT structures of individual detector elements are at least partially integrated into the CMOS ASIC wafer. MEMS heating elements are integrated with the PMUT structures by integrating under the PMUT structures in the CMOS wafer and/or over the PMUT structures (e.g., in the protective layer). For example, embodiments can avoid wafer bonding and can reduce other post processing involved with conventional manufacturing of PMUT ultrasonic sensors, while also improving thermal response.

Systems and methods resolve stresses in additive manufacturing. A stress resolution profile including frequency and amplitude parameters of an ultrasonic input are determined based on physical properties of the product. Successive layers of a material are added and energy is applied to incorporate the material of each layer into the product. An ultrasonic input is applied with the determined parameters to resolve stress as the product is built up. The ultrasonic input is varied as a depth of the material incorporated into the product increases.

An ultrasonic apparatus including a plurality of channels, each includes a transmission channel configured to generate and output a transmission signal based on a synchronization signal; a transducer element configured to convert the transmission signal output from the transmission channel into an ultrasonic signal and output the ultrasonic signal; a transceiver switching circuit configured to attenuate and output the transmission signal output from the transmission channel, and to output a reception signal that returns after the ultrasonic signal is transmitted to an object and is reflected from the object; and a reception channel configured to receive the attenuated output transmission signal and the output reception signal, and to detect transmission waveform information based on the attenuated transmission signal. The ultrasonic apparatus may further include a controller configured to store reference waveform information according to a transmission condition, and to compare the detected transmission waveform information with the reference waveform information.

Various sensors, sensor controllers, and sensor control methods are provided with model-based sideband balancing. In one illustrative embodiment, a controller for a piezoelectric transducer includes a transmitter, a receiver, and a processing circuit coupled to the transmitter and receiver. The processing circuit performs calibration and echo detection, the calibration including: sensing the piezoelectric transducer's phase response as a function of frequency; deriving equivalent circuit parameters for the piezoelectric transducer from the phase response; and determining a sideband imbalance based on one or more of the equivalent circuit parameters. Once the sideband imbalance is identified, the processing circuit may perform echo-detection processing that accounts for the sideband imbalance.

The invention refers to a driving circuit (2) for a piezoelectric ultrasonic transducer (4) in an ultrasonic transducer system (1), comprising: a transformer (21) having at least one primary-side winding (22, 22′, 22″); a switching unit having a semiconductor switch (24′, 24″) connected to the at least one primary-side winding (22, 22′, 22″) via a switched connection (A′, A″); and, a control unit (5) which is configured to alternately apply an operating voltage (U.sub.B) to the at least one primary-side winding (22, 22′, 22″) or to disconnect it therefrom, a protection circuit (25) which is electrically coupled to the switched connection (A′, A″) and which has a Zener diode (ZD1) which limits a switch-off voltage at the switched connection (A′, A″) in terms of magnitude to a limiting voltage (U.sub.G) which corresponds to at least twice the operating voltage.

An ultrasonic apparatus includes an ultrasonic transducer, a transmitting circuit, a receiving circuit, a Q-factor measuring circuit, and a frequency measuring circuit. The ultrasonic transducer is a three-terminal ultrasonic transducer that includes a transmitting electrode, a receiving electrode, and a common electrode. The transmitting circuit outputs a driving signal to the transmitting electrode to cause the ultrasonic transducer to transmit ultrasonic waves. The receiving circuit receives a receive signal from the receiving electrode. The frequency measuring circuit measures a resonant frequency of the ultrasonic transducer from a reverberation signal in the receive signal. The Q-factor measuring circuit measures a Q factor of the ultrasonic transducer from the reverberation signal in the receive signal.

An ultrasonic transducer having a piezoelectric element for use on a vehicle is disclosed. The transducer has a control and evaluation circuit for generating a control voltage for the piezoelectric element, which generates and emits an ultrasonic signal based on the control voltage, and for outputting an output signal on the basis of an echo signal received at the piezoelectric element. A gyrator circuit is included for providing a compensation inductance for adapting the control and evaluation circuit, for compensating for a parasitic connection capacitance of the piezoelectric element. The gyrator circuit has a variable compensation inductance. A method for compensating for an ultrasonic transducer having a piezoelectric element for adapting a reception sensitivity is also disclosed. The method involves recording a measurement variable for adapting the reception sensitivity, and compensating for the ultrasonic transducer by changing the compensation inductance of the gyrator circuit based on the recorded measurement variable.

Prior to manufacturing a product by additive manufacturing, a stress relief profile including frequency and amplitude parameters of an ultrasonic input is determined based on physical properties of the product, including resonant frequencies of the product and a material from which the product is manufactured. Successive layers of a material are added and energy is applied to incorporate the material of each layer into the product. A processor accesses stress relief profile parameters for each layer, determines whether a layer requires stress relief and determines a frequency and a power level for the stress relief at the layer. An ultrasonic input is applied with the determined parameters to relieve stress as the product is built up.

Methods and apparatuses provide a phacoemulsification probe, wherein the probe has a piezoelectric actuator coupled with a needle configured to be inserted into an eye of a patient; and a processor configured to sequentially drive the actuator electrically in a range of frequencies, to measure a respective electrical power input to the actuator at each of the frequencies in the range, to identify a frequency in the range of frequencies wherein a metric of the electrical power input is a maximum, and to estimate from the identified frequency a mechanical resonant frequency of the actuator, and to drive the actuator electrically at the mechanical resonant frequency.