Abstract:
There is disclosed an acoustic transducer (20) for communications within an operational bandwidth, the transducer comprising: A signal generator (22) for generating a signal at a centre-frequency within the operational bandwidth; A piezoelectric element (13) having a dielectric constant that varies with temperature; A driving electrode (12) at the surface of the piezoelectric element (13); A matching network (21), having a natural frequency at a given temperature, and operable to transfer the signal from the signal generator (22) to the piezoelectric element (13) whilst mitigating electrical loss, the matching network (21) being connected to the driving electrode (12); Wherein the matching network (21) comprises a temperature compensating capacitor (28) connected in parallel with the piezoelectric element (13), the temperature compensating capacitor (28) being for counteracting temperature-induced changes to the dielectric constant of the piezoelectric element (13) such that the electrical natural frequency of the transducer (20) is substantially constant over a range of temperatures.
Abstract:
An apparatus includes an array of pixels, each pixel including in-cell pixel logic and a piezoelectric micromechanical ultrasonic transducer (PMUT) element, each in-cell pixel logic being communicatively coupled with at least one adjacent pixel in the array. Transceiver electronics may operate the array in a selectable one of a first mode and a second mode. In the first mode, the array may generate a substantially plane ultrasonic wave. In the second mode, the array may generate, from at least one superpixel region, a focused beam of relatively high acoustic pressure, each superpixel region including at least one inner pixel disposed in a central portion of the superpixel region and at least a first group of outer pixels disposed in an outer portion of the superpixel region. The transceiver electronics may be configured to operate the array by configuring at least one in-cell pixel logic.
Abstract:
A piezoelectric micromechanical ultrasonic transducer (PMUT) includes a diaphragm disposed over a cavity, the diaphragm including a piezoelectric layer stack including a piezoelectric layer, a first electrode electrically coupled with transceiver circuitry, and a second electrode electrically coupled with the transceiver circuitry. The first electrode may be disposed in a first portion of the diaphragm, and the second electrode may be disposed in a second, separate, portion of the diaphragm. Each of the first and the second electrode is disposed on or proximate to a first surface of the piezoelectric layer, the first surface being opposite from the cavity. The PMUT is configured to transmit first ultrasonic signals by way of the first electrode during a first time period and to receive second ultrasonic signals by way of the second electrode during a second time period, the first time period and the second time period being at least partially overlapping.
Abstract:
An array of piezoelectric ultrasonic transducer elements includes a plurality of superpixel regions. Each superpixel region includes at least two pixel sets, a first pixel set of the at least two pixel sets being disposed in a central portion of the superpixel region, and at least a second pixel set being disposed in an outer portion of the superpixel region. An electrical coupling may be provided between the array and transceiver electronics. The transceiver electronics may be configured to operate the array in a selectable one of a first mode and a second mode. In the first mode, the array generates a substantially plane ultrasonic wave having a first acoustic pressure. In the second mode, the array generates, from each superpixel region, a focused beam having a second acoustic pressure that is substantially higher than the first acoustic pressure.
Abstract:
초음파 생성 장치는 초음파 변환기와 전기 펄스 생성 장치를 포함한다. 초음파 변환기는 전기 펄스 생성 장치로부터 전기 펄스를 수신하여 진동하는 압전소자, 그리고 초음파 변환기의 특성 정보를 저장하는 메모리를 포함한다. 그리고 전기 펄스 생성 장치는, 주파수, 전압, 및 전류 중 하나 이상이 가변 될 수 있는 전기 펄스를 생성하여 출력할 수 있도록 형성되는 가변 펄스 생성기, 상기 초음파 변환기의 특성 정보를 상기 메모리로부터 수신하는 정보 수신기, 그리고 상기 정보 수신기에 의해 수신되는 상기 특성 정보를 기초로 상기 가변 펄스 생성기가 주파수 및 전압, 전류 중 하나 이상이 가변 될 수 있는 전기 펄스를 생성하여 출력하도록 상기 가변 펄스 생성기를 제어하는 컨트롤러를 포함한다.
Abstract:
Phacoemulsification apparatus includes a phacoemulsification handpiece (30) having a needle and an electrical system for ultrasonically vibrating said needle along with a power source (16) for providing electrical power to the handpiece electrical system. Irrigation fluid is provided to the handpiece needle and aspirating fluid is removed from the handpiece needle. A determination of a voltage current phase relationship of the provided electrical power is made and in response thereto a control system (22) varies a power level duty cycle provided to the handpiece electrical system from the power source and/or modify the aspiration flow rate.