• 수산해양기술연구
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• 제35권3호
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• pp.312-322
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• 1999

A ultrasonic transduce with a single acoustic matching layer has been designed as an attempt to increase the bandwidth of underwater transducer. The wideband resonance condition was accomplished by attaching a single matching layer on the front face of a ceramic resonator composed of a piezoelectric bar, a taper part and a head part. A modified Mason's model was used for the performance analysis and the design of transducers, and the constructed transducers were tested experimentally and numerically by changing the impedance and thickness of the matching layer in the water tank.The obtained results are summarized as follows:1. Measured resonant and antiresonant frequencies of the piezoelectric transducer with no matching layer in air were 24.7 kHz and 25.6 kHz, respectively. 2. Two resonant frequencies of the piezoelectric transducer with a single matching layer were 21.7 kHx and 26.9 kHz, respectively, in air and 21.4 kHz and 22.7 kHz, respectively, with a water load.3. Two distinct resonance peaks in the transmitting voltage response(TVR) of the developed transducer were observed at 22.0 kHz and 25.8 kHz, respectively, with center frequency of 24.0 kHz. The values of TVR at these frequencies were 130.1 dB re $1 \muPa$/V at 22.0 kHz and 128.5 dB re $1 \muPa$/V at 25.8 kHz, respectively.Reasonable agreement between the experimental results and the numerical values was achieved.

• 한국결정성장학회지
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• 제26권6호
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• pp.252-257
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• 2016

Tonpilz 트랜스듀서를 이용한 미세먼지의 포집 거동을 살펴보기 위하여 유한요소법(FEM) 시뮬레이션을 이용하여 미세먼지의 응집 거동을 모사하였다. 원판형 head mass의 두께와 tail mass의 직경, 그리고 고정 볼트의 깊이를 트랜스듀서의 형상 변수로 고려하였다. 도넛형 압전체의 소재로는 기존의 PZT-4 소재와 서로 다른 특성의 두 가지 압전 단결정에 대하여 그 출력에 미치는 형상 변수의 최적화를 구현하였고 이를 통하여 얻은 트랜스듀서를 이용하였을 때 나타나는 미세먼지의 응집 거동을 다중 물리해석 S/W인 COMSOL을 이용하여 모사하였다.

• 한국전기전자재료학회논문지
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• 제24권1호
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• pp.22-26
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• 2011

On this paper, a circular unimorph-type piezoelectric transducer was proposed and studied. The transducer was fabricated by attaching a circular-shaped PZT ceramic to a circular plate of brass and output characteristics of the fabricated transducer were then analyzed and measured by changing driving points where the mechanical vibrations were applied. Two conditions depending on the location of vibration were respectively defined as a center forced model and an edge forced model. The resonance frequency and output voltage of the models were simulated by using ANSYS, a FEM(finite element method) program. Based on the results of the analyses, the vibration experiment was conducted and the output characteristics then measured through measurement equipment. As a result, the maximum output characteristics of two models were respectively generated at each resonance frequency and the resonance frequency of the center forced model was lower than the edge forced model.

• 한국정보통신학회논문지
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• 제3권3호
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• pp.559-567
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• 1999

결합형 유한요소-경계요소 기법을 사용하여 압전체 유연형 쏘나 변환기를 시뮬레이션하였다. 쏘나 변환기의 역학적 구동을 3차원적으로 모델링하였고 전기적 외부 부하 조건을 가지고 분석하였다. 정상 상태 변위 모드, 방향 패턴, 공진 주파수, 대역,0-factor, 출력 압력, TV 응답과 같은 결과들을 보여준다. 본 논문의 술통 형태의 압전 재질 쏘나 변환기는 유연한 변위를 발생시키며, 다른 형태의 쏘나 변환기와 달리 고출력, 낮은 Q-factor, 향상된 전방위성을 가지도록 해준다. 본 연구에서 개발된 쏘나 변환기 모델링의 결과를 ATILA와 같은 상업적 소프트웨어와 비교하였다.

• E2M - 전기 전자와 첨단 소재
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• 제8권2호
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• pp.211-216
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• 1995

In this study, the piezoelectric ceramics/polymer composite transducers with 1-3 connectivity have been studied. A piezoelectric ceramics PZT prepared by Wet-Dry Combination method was used as a filler in polymer matrix Eccogel. We've got the pulse-echo response for 1-3 type piezc-electric composite transducers in water. It was shown that the transmitting and receiving sensitivity of 1-3 type piezoelectric composite transducers could be improved in comparison with that- of solid PZT transducers. The reason is for that 1-3 type Piezoelectric composites have low dielectric constant and density. There was in a good agreement between the resonant frequencies calculated from one period and observed results on the Ultrasonic Transducer Analyzer. According to these results we could be figured out the distance in water by virture of the pulse-echo response.

• Structural Engineering and Mechanics
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• 제38권6호
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• pp.753-765
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• 2011

The radial vibration behaviors of a circular cylindrical composite piezoelectric transducer (CPT) are investigated. The CPT is composed of a piezoelectric ring polarized in the radial direction and an elastic ring graded in power-law variation form along the radial direction. The governing equations for plane stress state problem under the harmonic excitation are derived and the exact solutions for both piezoelectric and functionally graded elastic rings are obtained. The characteristic equations for resonant and anti-resonant frequencies are established. The presented methodology is fit to carry out the parametric investigation for composite piezoelectric transducers (CPTs) with arbitrary thickness in radial direction. With the aid of numerical analysis, the relationship between the radial vibration behaviors of the cylindrical CPT and the material inhomogeneity index of the functionally graded elastic ring as well as the geometric parameters of the CPTs are illustrated and some important features are reported.

• 한국음향학회지
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• 제41권3호
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• pp.278-286
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• 2022

본 연구에서는 압전세라믹 기반의 상용 Free-Flooded Ring(FFR) 트랜스듀서 대비 소형이면서 저주파 고감도 특성을 확보하기 위해, 높은 압전상수와 전기-기계 결합계수를 가지는 압전단결정 PIN-PMN-PT를 적용한 33-모드 FFR 트랜스듀서를 설계하였다. FFR 트랜스듀서의 광대역 특성을 확보하기 위해 비능동소자를 삽입한 링 구조를 적용하였으며, 3종의 비능동소자 소재 별 특성 해석 결과를 비교하여 최적의 소재를 선정하였다. 링 트랜스듀서의 특성 변화를 최소화하기 위해 오일 충진형 FFR 트랜스듀서로 제작하였으며, 음향시험을 통해 송신감도, 수중 임피던스 및 수평/수직 빔패턴이 해석결과와 잘 일치하는지 확인하였다. 해석 및 시험 결과를 비교한 결과, 송신감도는 공동공진 주파수에서 약 1.3 dB, 구조공진 주파수에서는 약 0.3 dB 차이를 보였다. 또한 상용 트랜스듀서 대비 높은 송신감도를 보유하면서도 직경을 약 17 % 축소하여 제작할 수 있었다. 이를 통해 소형이면서 고출력 특성을 가지는 압전단결정적용 FFR 트랜스듀서의 구현 가능성과 해석을 통한 특성 예측 방법의 유효성을 확인하였다.

• 한국군사과학기술학회지
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• 제12권3호
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• pp.282-289
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• 2009

This paper presents an estimation technique of the equivalent circuit parameters for an underwater acoustic piezoelectric transducer from the measured impedance. Estimated equivalent circuit can be used for the design of the impedance matching network of the sonar transmitter. A fitness function is proposed to minimize the error between the calculated impedance of the equivalent circuit and the measured impedance of the transducer. The equivalent circuit parameters are estimated by using the fitness function and the PSO(Particle Swarm Optimization) algorithm. The effectiveness of the proposed method is verified by the applications to a sandwich-type transducer and a dummy load. In addition, the impedance matching network is also designed by using the estimated equivalent circuit model.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 반도체 재료 센서 박막재료 전자세라믹스
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• pp.187-190
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• 2004

Transducer for ultrasonic linear motor with the symmetric and anti-symmetric modes was studied. The ultrasonic liner motor consists of two Lngevin type piezoelectric vibrators that cross at right angles with each other in tip. In order to excite symmetric and anti-symmetric mode, the transducer must have a 90 degree phase difference of voltage. Therefore, the tip of transducer moves on an elliptical motion. In this paper, the finite element analysis was used. The ultrasonic motor was fabricated using the simulated result and the driving characteristics were measured.

• 한국전기전자재료학회논문지
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• 제14권9호
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• pp.744-750
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• 2001

Higher directivity acoustic transducer using the self-demodulation effect was fabricated. The structure of transducer was designed such as dimension and support type of the piezoelectric element, the vibrating metal plate, and the housing case. Based on the design, the transducer was fabricated and measured its acoustic characteristics. Also, AM modulated driving circuit was designed for using the self-demodulation effect. The piezoelectric sounder with 200kHz resonant frequency and 20kHz bandwidth was designed by considering the sharp directivity and the sound pressure. The design and fabrication method worked in this study can be utilized in development of various speakers with higher directivity and broader bandwidth.