• 한국전기전자재료학회논문지
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• 제29권9호
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• pp.532-538
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• 2016

In this paper, a underwater acoustic Tonpilz transducer with the piezoelectric single crystal(72PMN-28PT) is developed. The thickness and the number of piezoelectric elements are theoretically designed with the equivalent circuit analysis to have the desired resonance frequency. In order to compare the performances, a piezoelectric ceramic transducer is also manufactured and their electrical impedance, TVR (transmitting voltage response), RVS (receiving voltage response) and beam pattern are compared.

• Journal of Magnetics
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• 제16권4호
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• pp.461-465
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• 2011

Traditional magnetostrictive/piezoelectric laminate composites are generally in the regular geometries such as rectangles or disks. To explore properties of the irregular geometry magnetostrictive/piezoelectric transducer in the fundamental resonant frequency, a step dumb-bell shaped Magnetoelectric (ME) transducer is presented in this study. Both analytical and experimental investigations are carried out for the dumb-bell shaped transducer in the fundamental frequency. Comparing with the traditional rectangular transducer, the theory shows the resonant frequency of dumb-bell shaped transducer is reduced 31%, and the experiment gives the result of that is 37% which is independent of dc magnetic fields. The ratio of magnetoelectric voltage coefficient (MEVC) between the dumb-bell shaped and rectangular shaped transducers in theory is 66% comparing with that of in experiment is varying from 140% to 33% when the dc field is increased from 0 Oe to 118 Oe.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.316-319
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• 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.

• JSTS:Journal of Semiconductor Technology and Science
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• 제5권1호
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• pp.17-23
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• 2005

This paper describes the simulation of a micromachined dome-shaped-diaphragm acoustic transducer built on a $1.5{\mu}m$ thick silicon nitride diaphragm ($2,000{\mu}m$ in radius, with a circular clamped boundary on a silicon substrate) with electrodes and piezoelectric ZnO film in a silicon substrate. Finite element analysis with ANSYS 5.6 has been performed to analyze the static and dynamic behaviors of the transducer under both pressure and voltage loadings.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2005년도 추계학술대회논문집
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• pp.911-914
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• 2005

The vibrational characteristics of the piezoelectric disc for a torsional vibration transducer is theoretically studied in this paper. The characteristic equation of the piezoelectric annular disc has been derived from Newton's End law and Gibb's free energy equations. With an anisotropic material property of the disc, the characteristic equation has yielded resonance frequencies. Numerically-calculated results were compared with the values obtained by finite element analysis and experiments

• 한국음향학회지
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• 제39권2호
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• pp.87-97
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• 2020

본 논문에서는 공기 중 광대역 초음파 방사용 압전 박막 기반 초소형 초음파 트랜스듀서(piezoelectric Micro-machined Ultrasonic Transducer, pMUT)의 설계 연구가 진행되었다. 하나의 트랜스듀서로 광대역을 달성하는 방법 중 하나는 다공진 시스템으로 설계하는 것이다. 새로운 pMUT은 박막 구조의 앞면과 뒷면에 적절한 음향 구조를 추가하여 다공진 시스템을 구현하도록 설계되었다. 박막 앞쪽은 도파관 구조로 모델링된 방사 파트로, 박막 뒷쪽은 음향 공동으로 모델링된 패키징 파트로 이루어져있다. 박막 파트, 방사 파트, 패키징 파트로 구성된 새로운 pMUT은 집중 변수 모델로 설계되었으며, 최종적으로 유한요소해석으로 검증되었다. 최종 설계된 pMUT은 102 kHz ~ 132 kHz (-3 dB)의 주파수 대역을 달성하였다.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1999년도 학술발표대회 논문집 제18권 1호
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• pp.218-223
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• 1999

A piezoelectric flextentional deep-water sonar transducer has been simulated using a coupled FE-BEM. The dynamics of the sonar transducer is modelled in three dimensions and is analyzed with extern리 electrical excitation conditions as well as external acoustic pressure loading conditions. Different results are available such as steady-state frequency response for RX and TX, displacement modes, directivity patterns, back-scattering patterns, resonant frequencies, bandwidths, quality factors, transmitting voltage (TV) responses, input receiving sensitivity (RS) responses. White the present barrel-stave typed sonar transducer of the piezoelectric material is being simulated, the external surface of the transducer is modified in order to allow the same water pressure to be applied to the inner and the outer surfaces of the transducer. With this modification for deep-water application, the resonance frequency of the modified flextentional sonar transducer becomes much lower than that of the unmodified flextentional sonar transducer. The results of the present sonar transducer modelling are also compared with those of a commercial package such as ATILA.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1283-1285
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• 1994

A three-layered piezoelectric ceramic transducer is fabricated with three piezoelectric ceramic disk transducers and two sheets of thin insulator. Its equvalent circuit is derived from the Mason's model of a thickness-driven piezoelectric transducer. We applied the electric input near its fundamental resonant frequency to the center transducer and connect the output voltages across the left and right transducers in series to the resistor load. Then we investigate the load characteristics at resonant frequencies under various resistor loads and the frequency characteristics near the resonant frequency under no load. Moreover, symbolic expressions for input impedances, voltage ratios, resonant frequencies, and bandwidths have been derived. The values calculated from those symbolic expressions are shown to agree well with the measurement values.

• 대한전자공학회논문지
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• 제23권4호
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• pp.515-521
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• 1986

Performances of a piezoelectric ultrasonic transducer are analyzed considering the internal losses of a piezoleelctric material and fabricated layers. The KLM-model is adopted for the equivalent circuit of a piezoelectric resonator, and the attenuation coefficient is introduced to represent the internal losses of the transducer. The attenuation coefficient of a piezoelectric resonator is inversely proportional to the maximum value of the input electrical resistance, and is confirmed to be an efficient parameter for the analysis of the considerable lossy piezo-electric resonator operating in a thickness mode. Also, the experimentla RTII is obtained by pulse-echo method. The experimental result is deviated from the predicted one within 3 dB over the 20dB frequency bandwidth.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.318-318
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• 2010

In this paper, we studied generating characteristic of cymbal type piezoelectric transducer according to change of cymbal cap. The transducer is composed of circular piezoelectric ceramic and two elastic bodies which are shaped as cymbal. Two elastic bodies are attached to upper and bottom of the ceramic. Principle of the transducer is to generate expanded displacement because vertical stress is transformed into horizontal stress by slope angle of elastic bodies. The transducer also has advantage of high durability by the angle of elastic bodies. In this study, each parameter was chosen, and then generating characteristics were analyzed by FEM program. The parameters were slope angle of cymbal cap (theta), cap height (h) and cap inner diameter(d). The model that had generating characteristic Of high voltage was chosen by results of the analysis. Besides, maximum vertical displacements according to change of vertical stress were analyzed by structural analysis in order to find out relation between the maximum vertical stress which can prevent from ceramic damage and conditions of each cap.