压电换能器阻抗匹配技术研究

超声测距传感器是由压电换能器及其收、发电路所组成的，其中压电换能器的阻抗特性直接影响着超声测距传感器的性能。为提高超声波回波信号的强度，扩大超声测距传感器的作用距离，对压电换能器的阻抗特性进行了分析与测试，设计了压电换能器的阻抗匹配电路，并进行了实验验证。     

具有阻抗匹配层的宽带纵向振动压电换能器设计

本文研究纵向振动压电换能器的频带展宽问题。在复合棒纵向换能器的辐射端加工适当材料的阻抗匹配层,可以使其工作在非单谐振状态下,在单层阻抗匹配层的情况下,合理地选择匹配层的厚度可以调整其谐振点之间的位置,从而改善换能器的辐射特性。本研究结果表明,对于机械品质因素Qm=6,发射响应带宽△f=4kHz的纵向振子,采用四分之一波长厚度的匹配层,在不降低发射响应的条件下,可展宽频带一倍以上。     

压电换能器的动态匹配

本文用合振荡的原理对太电换能器的匹配问题进行了分析，提出了一种关于匹配的新概念－动态匹配，强调了效率在匹配中的重要性。     

高频超声换能器的阻抗匹配研究

本文介绍了用于声学显微镜中超声换能器的阻抗匹配方法．由三个电感构成的T型结构被选作匹配网络，通过理论计算和实验调试得到了良好的匹配效果．文章的最后给出了实际的匹配结果．     

矩形扭转压电换能器的研制

本文从压电和机械振动等基本理论出发，首次较系统地建立了矩形扭转压电换能器的理论，推导出频率方程，并通过实验进行了验证。     

换能器的阻抗匹配设计

本文从基本的电学原理，详细推导出变压吕的互耦阻抗及变压器的阻抗变换关系，提出了换能器阻抗匹配较理想的设计方法，在工程设计中较好的实用价值。     

磁致伸缩超声换能器阻抗匹配网络的设计

根据磁致伸缩超声换能器的等效电路模型和阻抗匹配理论,该文设计了一种优化的π型匹配网络.该网络具有调谐、变阻和滤波的功能,适用于工作在中低频超声频率范围内的磁致伸缩超声换能器系统的阻抗匹配.仿真和实验结果表明:接入该π型阻抗匹配网络后,驱动电源与换能器之间实现了最大功率传输,换能器两端电信号的波形质量得到优化,换能器激励...     

压电复合材料换能器

压电复合材料是将压电陶瓷与聚合物材料按一定的连通方式、一定的体积百分比和一定的空间分布复合而成的。它可以提高材料的某些压电性能,并具有常用压电陶瓷材料所没有的某些优良性能。在过去的十几年中材料研究者们做了大量工作并取得实用性进展。     

面切变压电复合材料及其换能器

本文通过控制压电相在压复合材料中的分布工，把四块完全相同的等腰直角三角形２－２型压电复合拼材料拼接起来，四个直角顶点位于晶片的中心，     

干涉法测量Cymbal换能器的等效压电常量

在光学平板上用分立光学元件构建了迈克耳孙型分光束干涉仪,利用优化工艺制备的Cymbal换能器件作为核心单元,利用其在电场下的位移放大作用驱动平面反射镜,引起干涉图样的变化,实现了微位移及Cymbal换能器件等效压电常量的测定,并进行了非定域干涉图样变化的动态演示.     

A 2D equivalent circuit of piezoelectric ceramic ring for transducer design

In this paper a 2D equivalent circuit of longitudinally polarized piezoelectric ceramic rings is established, which is obtained as an approximated analytical solution of 3D constitutive equations in the hypothesis of axial symmetry when the shearing stress and torsion are ignored. The mechanical part of the equivalent circuit can be divided into two branches; one branch characterizes the longitudinal extensional vibration, the other represents the radial vibration. The two branches, which are coupled to an electrical port by two transformers separately, mechanically couple to each other by some mechanical impedance at the same time. Similar circuit is also presented when piezoelectric disk is concerned. Based on this model it is able to compute all the relations between the input applied voltage and the output forces and velocities on every external surface analytically. Compared with the 1D equivalent circuits, the 2D equivalent circuit gives a more comprehensive predicts of the thickness and radial modes with sufficient accuracy when the ring or disk is thin. When the ring or disk is so thick that the 1D theory is not validated, an effective predict of the coupled vibration can also be presented. Comparisons with the experimental results show this model is rather accuracy in frequency calculation.     

Interdigital transducer analysis using equivalent PSpice model

Interdigital transducers generating surface acoustic waves have found numerous applications. The present paper deals with an equivalent model of a single interdigital transducer as well as an SAW filter complying with the PSpice programme for the analysis of electronic systems. The suggested model makes it possible to take into account such effects as interelectrode reflections, losses along the acoustic path and the electromagnetic coupling between the transducers. The obtained results of the analysis of an interdigital transducer comply with the results obtained basing on an admittance model and delta-function model. The final aim is to model an SAW oscillator.     

Equivalent circuit of the non-uniform piezoelectric transducer

An equivalent circuit of the piezoelectric transducer with the step-by-step non-uniformity of piezoelectric properties is obtained by means of solving an inhomogenous wave equation by the method of Green's functions. Synthesis assumes that the transducer is governed by pure thickness vibrations. It is shown that the circuit is valid also for the transducer with piezoelectric properties continually varying from point to point. As an example of applying the equivalent circuit the maximum efficiency of electroacoustical transformation for a non-resonant transducer has been defined.     

弯张换能器的等效电路支路阻抗分析方法

本文提出了适用于弯张换能器的等效电路支路阻抗分析方法,归纳总结了一些描述IV型弯张换能器振动辐射的特性参量,通过支路阻抗分析方法计算这些特性量可以进行换能器局部结构的优化设计。     

变张换能器的等效电路支路阻抗分析方法

本文提出了适用于弯张换能器的等效电路支路阻抗分析方法,归纳总结了一些描述IV型弯张换能器振动辐射的特性参量,通过支路阻抗分析方法计算这些特性参量可以进行换能器局部结构的优化设计.     

A systems feedback representation of piezoelectric transducer operational impedance

An analysis of thickness-mode piezoelectric transducer impedance under a variety of mechanical load conditions is presented. A wideband, systems model is used to describe this impedance, which is representative of the electrical input impedance in the transmitting mode and the electrical output impedance for the receiving mode.For a fixed input voltage, the total current flowing through the transducer is considered as the vector sum of two current quantities. Firstly, an input current arising directly from the applied voltage source and secondly, a feedback current, which is generated by secondary piezoelectric action. By treating the problem in this manner, an extremely valuable insight into the nature of the electrical characteristics is provided. Complex variations in the impedance behaviour are readily explained and the physical processes that contribute to such deviations are clearly isolated.     

介观压电石英晶体等效电路的量子化

借鉴阻尼谐振子作量子力学处理的研究思想,将介观压电石英晶体等效电路量子化,在此基础上研究了真空态和压缩真空态下,各支路电流和电压的量子涨落. 关键词： 介观压电石英晶体 等效电路 阻尼谐振子 量子涨落     

Electric equivalent circuit of the circular piezoelectric resonator

The equivalent circuit for radial vibrations of circular ceramic resonator is solved by means of fictitious powers affecting the electrode boundaries and by series expansion. The influence of damping and internal friction is neglected. Theoretical relations were verified by measurements on resonators made from piezoelectric ceramics based on solid solutions of PbTiO₃-PbZrO₃.Devoted to Professor V. Petrílka on his sixty-fifth birthday.