Various methods and systems are provided for a multi-frequency transducer array. In one example, the transducer array is fabricated by forming an interdigitated structure from a first comb structure with a first sub-element and a second comb structure with a second sub-element. The interdigitated structure is coupled to a base package, a matching layer, and a backing layer to form a plurality of multi-frequency transducers.

A capacitive micromachined ultrasonic transducer having a wide reception band is provided. The capacitive micromachined ultrasonic transducer includes an element including a first sub-element and a second sub-element each including a cell. The cell includes a vibrating membrane that includes one of two electrodes formed with a spacing therebetween and that is vibratably supported. The capacitive micromachined ultrasonic transducer further includes a first detection circuit, a second detection circuit, and a combining circuit that combines a signal from the first detection circuit and a signal from the second detection circuit. The first sub-element is electrically connected to the first detection circuit, and the second sub-element is electrically connected to the second detection circuit. The first detection circuit and the second detection circuit have different cut-off frequencies.

The present disclosure provides a capacitive micro-machined ultrasonic transducer, a method for preparing the same, a panel, and a device, and belongs to the technical field of ultrasonic imaging. A capacitive micro-machined ultrasonic transducer includes a first electrode, a vibrating diaphragm layer and a second electrode that are arranged in order from bottom to top, a cavity existing between the first electrode and the vibrating diaphragm layer, in which the capacitive micro-machined ultrasonic transducer further includes a third electrode located on a surface of the vibrating diaphragm layer proximate to the cavity, an orthogonal projection of the third electrode on the first electrode covers a part of an orthogonal projection of the cavity on the first electrode. The technical solution of the present disclosure can realize the conversion of the frequency of the ultrasonic waves emitted by the capacitive micro-machined ultrasonic transducer.

A self-oscillating piezoelectric actuator drive circuit includes a integrating circuit; an inverter (INV1), inverters (INV2 and INV3) inverting an output signal of the inverter (INV1), sense resistors (Rs1 and Rs2) connected to output sides of the inverters (INV2 and INV3), a positive feedback resistor (Rfb2) feeding back an output signal of the inverters (INV2 and INV3) to the integrating circuit; and a negative feedback resistor (Rfb1) feeding back a voltage generated from the sense resistors (Rs1 and Rs2, Rs1<Rs2 in terms of a resistance value) to the integrating circuit. In a startup state, the sense resistor (Rs2) and the inverter (INV3) are selected, and in an operating state after the startup state, the sense resistor (Rs1) and the inverter (INV2) are selected.

A bat deterrent system to deter bats from approaching wind turbines may include a first deterrent box having a first and second transducer bank. The first transducer bank may include a first set of transducers located on a first plane and a second set of transducers located on a second plane. The second plane may be different from the first plane. The bat deterrent system may also include a second deterrent box having a third and fourth transducer bank. The third transducer bank may include a third set of transducers located on a third plane and a fourth set of transducers located on a fourth plane. The fourth plane may be different from the third plane. At least one transducer may simultaneously emit a different ultrasonic output waveform than the ultrasonic output waveform emitted from another transducer.

The invention relates to a method for electronically controlling the power supply to a multi-phase motor, said method comprising: supplying at least one phase of the motor with a suitable first periodic or pseudo-periodic electrical signal such that the electric motor and/or a structure linked to the motor emits a first sound signal, the above-mentioned first signal being supplied while a rotor of the motor is maintained immobile relative to a stator of the motor.

An ultrasonic/megasonic cleaning device includes a cleaning unit including an upper casing and a lower casing connected to form a hollow chamber, an ultrasonic/megasonic generator provided in the hollow chamber, and a bottom quartz component provided with a quartz rod array composed of a plurality of vertically arranged quartz rod-like structures; a spray arm connected to the upper casing; and an ultrasonic/megasonic frequency control unit connected between the at least one signal source and the ultrasonic/megasonic generator, for constantly varying a frequency of the electrical signal output from the at least one signal source and introducing the electrical signal into the ultrasonic/megasonic generator, so as to dynamically vary an oscillation frequency of the ultrasonic/megasonic wave generated by the ultrasonic/megasonic generator; wherein the ultrasonic/megasonic frequency control unit includes a frequency-switching timing control unit configured to trigger am ultrasonic/megasonic frequency switching control unit to switch the oscillation frequency of the ultrasonic/megasonic wave from a first frequency to a second frequency when the ultrasonic/megasonic wave has been generated at the first frequency for a time period, the time period being randomly selected within a time range.

Disclosed herein a method of producing an ultrasound that includes defining a set of criteria for an ultrasound emitter comprising a plate. The set of criteria includes a power output criterion, a frequency criterion and number of nodes for a resonance mode of the plate, a focus criterion, and a durability criterion. The method includes determining an outline and a thickness range for the plate, based on the set of criteria. The method includes using topology optimization to determine internodal zone dimensions for the plate, based on the set of criteria, the outline, and the thickness range. The method includes manufacturing the plate according to the internodal zone dimensions.

A method for removing foreign substances from a camera system is provided. The camera system includes a camera device with a transparent cover having a piezoelectric component. First, a type of the foreign substances is identified based on temperature, an image captured by the camera system, and a voltage change of the piezoelectric component. A sequence of frequencies is applied to the piezoelectric component and a resonant frequency is acquired. Thereafter, the foreign substances are removed from the camera system. A vibration frequency and a vibration time period for the piezoelectric component are determined according to the identified type of the foreign substances. The vibration frequency is based on the resonant frequency. The piezoelectric component is driven with the vibration frequency and the vibration time period, such that at least a portion of the foreign substances are removed from the transparent cover through vibration of the piezoelectric component.

An ultrasonic array oscillator according to the present technology includes ultrasonic oscillators and semiconductor chips. The ultrasonic oscillators form an array. The semiconductor chips are bonded to the respective ultrasonic oscillators to form impedance matching circuits.