• Title, Summary, Keyword: Piezoelectric resonator

Search Result 101, Processing Time 0.04 seconds

3-D underwater object restoration using ultrasonic transducer fabricated with porous piezoelectric resonator and neural network (다공질 압전소자로 제작한 초음파 트랜스듀서와 신경회로망을 이용한 3차원 수중 물체복원)

  • 조현철;박정학;사공건
    • Electrical & Electronic Materials
    • /
    • v.9 no.8
    • /
    • pp.825-830
    • /
    • 1996
  • In this study, Characteristics of Ultrasonic Transducer fabricated with porous piezoelectric resonator, 3-D underwater object restoration using the self made ultrasonic transducer and modified SCL(Simple Competitive Learning) neural network are investigated. The self-made transducer was satisfied the required condition of ultrasonic transducer in water, and the modified SCL neural network using the acquired object data 16*16 low resolution image was used for object restoration of $32{\times}32$ high resolution image. The experimental results have shown that the ultrasonic transducer fabricated with porous piezoelectric resonator could be applied for SONAR system.

  • PDF

Experimental Verification of the Unified Formula for Electromechanical Coupling Coefficient of Piezoelectric Resonators

  • Kim, Jung-Soon;Kim, Moo-Joon;Ha, Kang-Lyeol;Cao, Wen-Wu
    • The Journal of the Acoustical Society of Korea
    • /
    • v.25 no.3E
    • /
    • pp.110-114
    • /
    • 2006
  • In a previous theoretical paper, we have derived a unified formula by considering 2-D coupled mode vibrations. The unified formula for electromechanical coupling coefficient of piezoelectric resonator was verified experimentally. The capacitance change near the resonant frequency was investigated to estimate the effective coupling coefficient of the resonator instead of the conventional method based on I-D model. The susceptance spectra were measured for the seven samples of piezoelectric resonator with different aspect ratio. Excellent agreement between theoretical and experimental results was obtained.

3-D Underwater Object Recognition Using Ultrasonic Transducer Fabricated with Porous Piezoelectric Resonator (다공질 압전 초음파 트랜스튜서를 이용한 3차원 수중 물체인식)

  • 조현철;이수호;박정학;사공건
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.316-319
    • /
    • 1996
  • In this study, characteristics of ultrasonic transducer fabricated with porous piezoelectric resonator are investigated, 3-D underwater object recognition using the self-made ultrasonic transducer and SOFM(Self-Organizing Feature Map) neural network are presented. The self-made transducer was satisfied the required condition of ultrasonic transducer in water, and the recognition rates for the training data and the testing data were 100 and 95.3% respectively. The experimental results have shown that the ultrasonic transducer fabricated with porous piezoelectric resonator could be applied for sonar system.

  • PDF

Design of sandwich type piezoelectric resonator for underwater acoustic transducer (수중 음향 트랜스듀서용 샌드위치형 압전 진동체의 설계)

  • 조치영;김인수;윤형규
    • Journal of KSNVE
    • /
    • v.5 no.4
    • /
    • pp.577-583
    • /
    • 1995
  • The sandwich type piezoelectric resonator is widely used for the acoustic sources of underwater acoustic transducers, whose important design parameters are shapes, materials, dimensions and supporting methods. Practical design method of resonators consists of manufacturing, experiments and modification so that it requires much time and expenses. In this study, an analytical design method of sandwich type piezoelectric resonators is presented based on the nonlinear optimization technique. The proposed method is applied to the design of an example resonator model in order to maximize the output powers. For the investigation of performance according to the division and their electrical connection, three types of resonators are manufactured. In addition, their dynamic characteristics such as electrical admittance and transmitting voltage response are measured and compared.

  • PDF

Characteristics of 3-D Underwater Object Recognition Independent of Translation Using Ultrasonic Sensor Fabricated with Porous Piezoelectric Resonator (다공질 압전소자로 제작한 초음파 센서의 물체변위에 무관한 3차원 수중 물체인식 특성)

  • 조현철;이기성;박정학;이수호;사공건
    • Electrical & Electronic Materials
    • /
    • v.10 no.9
    • /
    • pp.916-921
    • /
    • 1997
  • In this study Characteristics of 3-D underwater object recognition independent of translation using the self-made ultrasonic sensor fabricated with porous piezoelectric resonator and presented. The sensor was satisfied with requirement of ultrasonic sensor. The recognition rates for the training data and the testing data are 97.45 and 91.25[%] respectively using the self-made ultrasonic sensor and SCL(Simple Competitive Learning) neural network. According to the experimental results It is believed that the self-made ultrasonic sensor can be applied as sensor of SONAR system.

  • PDF

Characteristics of ZnO Thin Film for SMR-typed FBAR Fabrication (FBAR 소자제작을 위한 ZnO 박막 증착 및 특성)

  • Shin, Young-Hwa;Kwon, Sang-Jik;Kim, Hyung-Jun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.18 no.2
    • /
    • pp.159-163
    • /
    • 2005
  • This paper gives characterization of ZnO thin film deposited by RF magnetron sputtering method, which is concerned in deposition process and device fabrication process, to fabricate solidly mounted resonator(SMR)-type film bulk acoustic resonator(FBAR). A piezoelectric layer of 1.1${\mu}{\textrm}{m}$ thick ZnO thin films were grown on thermally oxidized SiO$_2$(3000 $\AA$)/Si substrate layers by RF magnetron sputtering at the room temperature. The highly c-axis oriented ZnO thin film was obtained at the conditions of 265 W of RF power, 10 mtorr of working pressure, and 50/50 of Ar/O$_2$ gas ratio. The piezoelectric-active area was 50 ${\mu}{\textrm}{m}$${\times}$50${\mu}{\textrm}{m}$, and the thickness of ZnO film and Al-3 % Cu electrode were 1.4 ${\mu}{\textrm}{m}$ and 180${\mu}{\textrm}{m}$, respectively. Its series and parallel frequencies appeared at 2.128 and 2.151 GHz, respectively, and the qualify factor of the resonator was as high as 401.8$\pm$8.5.

Effect of Electrodes on the Electrical Properties of Piezoelectric Ceramic Transformer (장방형 압전세라믹변압기의 전극형상이 전기적특성에 미치는 영향)

  • 정수태;최상수;조상희
    • Electrical & Electronic Materials
    • /
    • v.10 no.6
    • /
    • pp.562-569
    • /
    • 1997
  • The resonance characteristics on vibration mode of a transverse type ceramic resonator and the output voltage characteristics of a piezoelectric ceramic transformer are discussed in the effects of partial electrode arrangement (one sided, centered and both sided). A resonance characteristics of resonator depended strongly on both a vibration mode and a electrode structure because of a strain distribution. The maximum resonance current of a piezoelectric ceramic transformer [PCT] with partial centered electrode appeared in λ/2 mode, and that of a PCT with partial both sided electrode appeared in 3λ/2 mode. But the maximum output voltage of those samples appeared in λ/2 mode. In the PCT with partial both sided electrode, the ration of output voltage to input current was highest out of all samples and the poling voltage was a half times of 깬두 type transformer.

  • PDF

3D modeling of a surface acoustic wave for wireless sensors (무선 센서용 표면탄성파의 3 차원 모델링)

  • Cuong, Tran Ngoc;Chung, Gwiy-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.111-111
    • /
    • 2009
  • In this work, we discuss simulation of surface acoustic wave device using Comsol Multiphysics. The structure SAW device based on piezoelectric thin film aluminum-nitride (AlN) on silicon was simulated. Some parameters of SAW device such as surface velocity, displacement of piezoelectric thin film were evaluated by software. Many modes and shapes of wave are also discussed in this paper. For evaluation physical parameters of AlN piezoelectric layer, the SAW resonator was modeled and simulation results were also compared with experiment results. we simulated arid evaluated the surface Rayleigh wave of AlN thin film on silicon substrate. Results simulation and experiment showed the surface velocity of AlN thin film was about 5200 m/s and shape of surface wave was also displayed. This paper has also proposed as method to study SAW characteristic of piezoelectric thin film and found out measurement values accurately of film such as stiffness matrix, piezoelectric matrix. These values are very important in calculation and design SAW device or MEMS device based on AlN piezoelectric layer.

  • PDF

Film Bulk Acoustic Wave Resonator using surface micromachining (표면 마이크로머시닝을 이용한 압전 박막 공진기 제작)

  • 김인태;박은권;이시형;이수현;이윤희
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • /
    • pp.156-159
    • /
    • 2002
  • Film Bulk Acoustic wave Resonator (FBAR) using thin piezoelectric films can be fabricated as monolithic integrated devices with compatibility to semiconductor process, leading to small size, low cost and high Q RF circuit elements with wide applications in communications area. This paper presents a MMIC compatible Suspended FBAR using surface micromachining. It is possible to make Si$_3$N$_4$/SiO$_2$/Si$_3$N$_4$membrane by using surface micromachining and its good effect is to remove the substrate silicon loss. FBAR was made on 2$\mu\textrm{m}$ multi-layered membrane using CVD process. According to our result, Fabricated film bulk acoustic wave resonator has two adventages. First, in the respect of device Process, our Process of the resonator using surface micromachining is very simple better than that of resonator using bull micromachining. Second, because of using the multiple layer, thermal expansion coefficient is compensated, so, the stress of thin film is reduced.

  • PDF

A Study on the Evaluation of Piezoelectric Thin Film Characteristics in Composite Resonator Structure Using Resonance Spectrum Method (공진주파수 스펙트럼법을 이용한 Composite Resonator 구조에서 압전박막의 특성 평가에 대한 연구)

  • Choi Joon Young;Chang Dong Hoon;Kang Seong Jun;Yoon Yung Sup
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.42 no.1
    • /
    • pp.9-17
    • /
    • 2005
  • We studied the characteristics of impedance and electromechanical coupling coefficient in ZnO and AIN thin films by using resonance frequency spectrum method. The response peak of impedance decreased with the decrease of thickness of piezoelectrics, the number of mode of response peak decreased with the decrease of substrate thickness. An error of Kt² estimated from input Kt² increased as the thickness of piezoelectrics decreased and the thickness of substrate increased. Also, the error was increased in case of a large acoustic impedance of substrate. It was found that the composite resonator operating in optimized condition could be designed through the resonance frequency spectrum analysis of composited resonator consisted of piezoelectric thin film and substrate.