首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 78 毫秒
1.
圆形振动膜ZnO压电微传声器的研制   总被引:1,自引:0,他引:1       下载免费PDF全文
本文介绍了一种新型圆形振动膜ZnO压电微传声器的制备,并对传声器制备的工艺过程进行了较为详细的描述。圆形振动膜的压电传卢器与以前方形振动膜结构设计相比,较大幅度提高了传声器的灵敏度和成品率,灵敏度达到-70dB(相对于1V/Pa),成品率达到80%。  相似文献   

2.
周瑜  刘超  王坤博  魏晓村 《光学学报》2019,39(1):300-306
针对基于相位解调的双光束薄膜干涉型光纤传声器的特性展开了研究,仿真分析了三路信号的直流分项、交流分项以及相位差对双光束薄膜干涉型光纤传声器输出性能的影响。采用对比法,并通过实验研究了基于相位解调的双光束薄膜干涉型光纤传声器的输出特性,实现了灵敏度为193 mV/Pa@1 kHz、频率响应为200 Hz~4 kHz@±3 dB的声信号测量。本研究能够很好地应用于声探测、语音识别等领域。  相似文献   

3.
提出了一种基于ZnO压电薄膜的硅微压电矢量水听器,其核心部件是利用微电子机械系统(MEMS)技术制作的悬臂梁结构压电加速度计。由近似解析和有限元分析,得出加速度计的灵敏度和谐振频率,并在此基础上对其进行了优化设计。研制了MEMS压电加速度计,并装配后构成MEMS矢量水听器。测试结果表明:加速度灵敏度在20~1,200 Hz范围内约为0.83 mV/(m/s~2)。经过液柱法测量,在1 kHz时,MEMS矢量水听器等效声压灵敏度为-229.5 dB(ref.1V/μPa),比同类型压阻式MEMS矢量水听器的灵敏度高17 dB以上。  相似文献   

4.
采用微硅 锆钛酸铅(Si-PZT)悬臂梁结构并在悬臂梁末端附加镍质量块,构成可以工作于低频环境(小于1 000 Hz)的微压电能量采集器,一种利用压电效应将环境振动能转换为电能的器件。利用金薄膜作为中间层的共晶键合技术和PZT研磨减薄技术制备了微压电悬臂梁结构,PZT减薄实验最好结果为减薄至8 m。镍质量块(2 mm2 mm0.6 mm)采用微电铸工艺制备。通过对硅片与块材PZT的共晶键合工艺与PZT减薄技术的研究,制备出总厚度约为71 m的Si-PZT悬臂梁结构,其中硅梁厚约为47 m,PZT梁厚约为24 m。制备的微压电振动能量采集器样品的测试结果表明:在谐振频率为950 Hz,1.0g加速度激励条件下,其交流输出峰值电压可达958 mV。  相似文献   

5.
针对开口房间内的变压器,在开口处布放若干扬声器和误差传声器构成虚拟声屏障,实验研究了虚拟声屏障对通过开口向外辐射的低频线谱噪声的控制效果。将15个次级源近似均匀分布在面积为2 m′ 2.7 m的开口面上,左右间距约58.5 cm、上下间距45-65 cm,15个误差传声器分别位于对应的次级源正前方1 m,系统采用自适应谐波降噪算法。结果表明:虚拟声屏障系统在误差点100 Hz、200 Hz和300 Hz的平均降噪量分别达到12.7 dB、19.9 dB和22.2 dB,虚拟声屏障对100 Hz、200 Hz、300 Hz线谱噪声的控制效果与单层封闭窗户相当,且内部合成参考信号,无需外接参考传声器。采用虚拟声屏障对开口房间内的变压器降噪的好处是实现室内外的自然通风,便于变压器的散热。  相似文献   

6.
开缝压电圆环深海水听器   总被引:3,自引:0,他引:3       下载免费PDF全文
卢苇  蓝宇  石桂欣 《声学学报》2017,42(6):721-728
利用能量法得到了开缝压电圆环水中的谐振频率方程与电导纳曲线;通过构建开缝压电圆环低频接收状态等效电路图,推导了开缝压电圆环低频开路电压灵敏度;比较开缝压电圆环和整体圆环低频接收灵敏度,提出了利用开缝压电陶瓷圆环与溢流结构相结合设计深海水听器的思路;通过建立溢流式开缝压电圆环有限元仿真模型,探讨了开缝压电圆环的低频开路电压灵敏度与圆环结构参数的关系。经过仿真优化,研制了水中谐振频率600 Hz的开缝压电圆环深海水听器。水池声学测试与耐压测试结果表明,溢流式开缝压电圆环水听器在100~300 Hz频段内低频开路电压灵敏度最大值为-193.2 dB,最小值-197.9 dB,起伏-4.7 dB,耐静水压30 MPa;与采用相同尺寸压电元件的溢流圆环水听器相比,溢流式开缝压电圆环水听器的低频开路电压灵敏度提高20 dB;验证了本文提出的采用开缝压电圆环构建深海水听器的实用性。   相似文献   

7.
设计并制作了一种光纤微悬臂梁传感器,由于悬臂梁在受迫振动过程中不会产生拉伸变形,与四周固定的圆形密闭薄膜相比,会产生更高的声波灵敏度。采用飞秒激光加工制作微悬臂梁薄膜光纤声波传感器,制备出长宽均为500μm,厚6μm的微悬臂梁结构。通过实验得到其反射光谱对比度为8.8 dB,自由光谱范围为7.72 nm,理论计算得光纤法布里-珀罗腔长为155.6μm。研究结果表明,该光纤声波传感器在2 200 Hz处出现明显的共振峰,对应的声压灵敏度为414 mV/Pa,在300 Hz时有最大的灵敏度675 mV/Pa,与普通硅橡胶薄膜声波传感器相比灵敏度显著提高。理论计算硅橡胶微悬臂梁光纤声波传感器的一阶共振频率为198 Hz,与实验测得的共振频率较为接近。同时悬臂梁传感器的声压灵敏度可达675 mV/Pa,声压响应线性度为0.994。  相似文献   

8.
针对普通薄膜型降噪结构的吸声性能较差和吸声带宽较窄的问题,本文设计了一种微穿孔的介电弹性体薄膜吸声结构。该结构由穿孔的介电弹性体薄膜与背腔组合而成,目的是拓宽介电弹性体薄膜低频率段的吸声带宽。针对微穿孔的介电弹性体薄膜吸声结构,从试验角度分析穿孔薄膜初始厚度、穿孔孔径及穿孔间距对结构吸声性能的影响。分析结果可知:通过适当增加薄膜的初始厚度,薄膜的整体吸声性能得到有效提升,最大可将319Hz吸声频带的吸声系数从0.2提升至0.7;减小薄膜的穿孔孔径能够有效拓宽穿孔薄膜的吸声频带,可使吸声系数0.4以上的吸声带宽由304Hz拓宽至432Hz;适当控制穿孔间距能够达到更好的吸声效果。  相似文献   

9.
本文对高声压传声器校准器,腔内声压级受传声器前腔体积的影响进行了计算和测量,并叙述了校准方法。结果表明,保持校准器插入电压不变的条件下,在其工作频率范围内,传声器前腔体积变化,会使校准器腔内的声压级随频率产生不同程度的变化。若不对传声器前腔体积的影响进行修正,会带来多达几分贝的校准误差。本文采用前腔体积已知的标准传声器和激光测振仪测量腔体积,并采用激光测振仪测量活塞振幅的方法来校准高压传声器校准器.校准的声压级范围为124dB—164dB,校准精确度为±0.27dB。  相似文献   

10.
对所研制的硅微压电超声换能器(PMUT)的振动特性进行了研究分析。对硅微压电超声换能的振动膜薄板的厚度相对于薄板的尺度(边长)而言较薄的情况,理论分析与实验结果均表明残余应力对换能器的谐振频率影响较大:不考虑残余应力的理论分析得出的换能器谐振频率与器件的实验测量的结果相差较大,而考虑残余应力的分析给出的谐振频率结果与实验结果是符合的。本文还对所制作的硅微压电超声换能器的谐振频率及导纳进行测量,并给出其等效电路参数。其中振动膜边长为1mm的换能器的谐振频率为71.25 kHz。最后对其进行了简单接收发射实验,测得谐振频率处的接收灵敏度为-201.6 dB(ref 1 V/μPa),发射电压响应约为137 dB(ref 1μPa·m/V)。  相似文献   

11.
Measurements were made to determine the effect of air-flow on the sensitivity of microphone phobes. Standard condenser microphones fitted with either a standard nose cone or a slit-tube were investigated. A slit-tube is a special device to suppress the turbulent noise signal when sound measurements are to be made within a flow. The experiments show that there is a loss of the acoustic sensitivity due to the air-flow. However, the mean sensitivity loss is less than 0·5 dB up to 40 m/s and within a frequency range from 40 Hz to 1250 Hz. Therefore the loss in sensitivity may be neglected for most practical measurements.  相似文献   

12.
声传感器和光声池是激光光声光谱技术的核心组件。结合光纤迈克耳孙干涉仪、相位载波解调技术和纵向共振光声池,提出一种共光声池腔的芯轴型空气衬底光纤麦克风。光纤麦克风中的铜毛细管被用作光声池的共振腔,传感臂由10 m长的超细光纤缠绕在铜毛细管上构成,参考臂为5 cm长的短臂且已进行隔声隔振处理。基于结构共振频率稳定的特点,优化光纤麦克风的共振频率,使其略低于光声池的一阶纵向共振频率,以实现准双共振。实验结果表明,麦克风在共振频率为1443 Hz处的最小可检测声压为0.69μPa√Hz。在1 kHz处,声压电压响应线性度为99.98%(5 mPa~3 Pa),动态范围为112.52 dB。该光纤麦克风适用于高温、易爆和高电磁干扰等特殊环境下痕量气体的高精度检测。  相似文献   

13.
The potential of a piezoelectric, double-amplifier active-skin with structural acoustic sensing (SAS) is demonstrated for the reduction of broadband acoustic radiation from a clamped, aluminum plate. The active-skin is a continuous covering of the vibrating portions of the plate with active, independently controllable piezoelectric, double-amplifier elements and is designed to affect control by altering the continuous structural radiation impedance rather than structural vibration. In simulation, acoustic models are sought for the primary and secondary sources that incorporate finite element methods. Simulation indicates that a total radiated power attenuation in excess of 10 dB may be achieved between 250 and 750 Hz with microphone error sensing, while under SAS the radiated power is reduced by nearly 8 dB in the same frequency range. In experiment, the adaptive feed forward filtered-x LMS (least mean square) algorithm, implemented on a Texas Instruments C40 DSP, was used in conjunction with the 6I6O control system. With microphone error sensing, 11.8-dB attenuation was achieved in the overall radiated power between 175 and 600 Hz, while inclusion of SAS resulted in a 7.3-dB overall power reduction in this frequency band.  相似文献   

14.
殷昊  刘伟  冯秀娟  庞新良 《应用声学》2023,42(2):304-311
为克服现有主流型活塞式次声校正器低频端漏气误差增大的缺点,该文提出基于扬声器激励、薄膜密封结构作为标准次声源,实现了一种新型次声校准装置。该装置采用成熟化技术方案和模块化设计,具有组装方便、体积小、重量轻和工作稳定等优点。目前在校准频率0.1~20 Hz范围内,合成标准不确定度在0.2 dB以内,扩展不确定度优于0.4 dB (k=2)。利用该装置分别对MB3a型和自研次声传感器进行了校准,前者的校准结果与产品技术参数一致,后者与中国计量科学研究院的校准结果相近(误差小于7.5%),测试结果表明该装置可用于次声传感器的校准。值得注意的是,该校正器可能做到低端0.01 Hz或更低的频率的绝对校正,该文展望了扬声器激励次声校正器发展前景。  相似文献   

15.
The variation of wind noise at hearing-aid microphones with wind speed, wind azimuth, and hearing-aid style was investigated. Comparisons were made across behind-the-ear (BTE) and completely-in-canal (CIC) devices, and between microphones within BTE devices. One CIC device and two BTE devices were placed on a Knowles Electronics Manikin for Acoustic Research. The smaller BTE device had vented plastic windshields around its microphone ports while the larger BTE device had none. The microphone output signals were digitally recorded in wind generated at 0, 3, 6, and 12 m/s at 8 wind azimuths. The microphone output signals were saturated at 12 m/s with wind-noise levels of up to 116 dB SPL at the microphone output. Wind-noise levels differed by up to 12 dB between microphones within the same BTE device, and across BTE devices by up to 6 or 8 dB for front or rear microphones, respectively. On average, wind-noise levels were lowest with the CIC device and highest at the rear microphone of the smaller BTE device. Engineering and clinical implications are discussed.  相似文献   

16.
The errors due to developmental finite difference approximations in the two-microphone acoustic intensity measurement technique are considered in this paper. Equations are developed which describe the errors in intensity measurements for point monopoles, dipoles, and lateral quadrupoles. High accuracy is shown possible with careful selection of measurement parameters for each of these sources. For a microphone separation of 8 mm approximation errors are shown to be less than 2 dB from 0 to 10 000 Hz. For the quadrupole source low frequency errors not present with other sources are demonstrated. A lower limiting frequency for intensity measurements is determined to prevent these low frequency errors.  相似文献   

17.
如何消除气流的影响是管道有源降噪的难点之一,本文分析了湍流对有源降噪系统的影响,并开发了一种抗湍流传声器探管,最后在某种通风系统的进气管段进行了降噪试验,气流速度为20m/s时,在60-630Hz频带取得了15dB(A)的降噪效果。  相似文献   

18.
This paper presents the theory, design, and validation of a microphone calibrator used to simultaneously calibrate the amplitudes of multiple microphones on a single probe. The probe uses four 6 mm diameter electret microphones to acquire the data needed to compute acoustic energy density. This probe has prompted the need for simultaneous, multi-microphone amplitude calibration. The calibration process simultaneously subject each microphone on the probe to the same known acoustic pressure using four equal-length, small-diameter tubes connected to a single excitation source. A reference microphone connected to a fifth tube is used to calibrate the microphones. Test results show that the calibrator can calibrate each probe microphone within ±0.5 dB up to 2 kHz, and within ±1 dB up to 4.9 Hz with a confidence level of 95%.  相似文献   

19.
Noise in miniature microphones   总被引:2,自引:0,他引:2  
The internal noise spectrum in miniature electret microphones of the type used in the manufacture of hearing aids is measured. An analogous circuit model of the microphone is empirically fit to the measured data and used to determine the important sources of noise within the microphone. The dominant noise source is found to depend on the frequency. Below 40 Hz and above 9 kHz, the dominant source is electrical noise from the amplifier circuit needed to buffer the electrical signal from the microphone diaphragm. Between approximately 40 Hz and 1 kHz, the dominant source is thermal noise originating in the acoustic flow resistance of the small hole pierced in the diaphragm to equalize barometric pressure. Between approximately 1 kHz and 9 kHz, the noise originates in the acoustic flow resistances of sound entering the microphone and propagating to the diaphragm. To further reduce the microphone internal noise in the audio band requires attacking these sources. A prototype microphone having reduced acoustical noise is measured and discussed.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号