세라믹 필터의 帶域幅 調整에 관한 硏究

宋埈泰 成均館大學校 1983 論文集 Vol.33 No.-

This paper showed the technique how to change the bandwidth of ceramic filter at will. The resonant mode of trapezoid type ceramic filter is synthesized by the resonant mode of the major side and the minor side independently, so the bandwidth is broadened. In this result if some constants of ceramic filter are known, two port ceramic filter showing a wanted bandwidth can be fabricated easily. In those computer simulations. the bandwidths were changed from 3.2kHz to 6.4 kHz in sample A, and from 5. 1kHz to 10.2 kHz in sample B.

요철반사기에서 표면파의 해석 ( The Analysis of the Surface Waves By Arrays of Reflecting Grooves )

송준태,H. F. Tiersten 대한전자공학회 1987 대한전자공학회 학술대회 Vol.1987 No.7

초음파 현미경의 음향 렌즈 설계에 관한 연구

宋埈泰,張洪寬 成均館大學校 科學技術硏究所 1992 論文集 Vol.43 No.1

The design of piezoelectric layer and acoustic lens for scanning acoustic microscope is described. Acoustic lens utilizes the principle of optical lens, but it is the concave type in contrast with the optical lens. Mainly, the materials of acoustic lens are composed of ZnO which operates the longitudinal mode and has a large electromechanical coupling constant with the piezoelectric transducer and A1_20_3 which is very hard and whose difference of acoustic velocity is large about the acoustic lens rod. The segment of entire circle(O) must be generally 50˚ which is larger than Rayleigh's critical angle. If θ_max is 50˚ K is 53.33 or 15.74. Thus, according to the frequency of piezoelectric transducer, the radius of top electrode is obtained by formula (4.16). Peizoelectric transducer must be the thickness mode of circular plate, and piezoelectric layer is between λ / 4 and λ/2. And with the frequency of half wavelength of f_o = ω_o/2π = v_o/21_o and the acoustic velocity of v_0, the thickness of 1_0, the thickness of transducer is taken.

태양광-연료 변환을 위한 3C-SiC 반도체 광전극의 연구 및 향후 전망

송준태,오지훈 한국세라믹학회 2015 세라미스트 Vol.18 No.2

9.5/65/35 PLZT를 이용한 Color filtering 특성에 관한 연구

宋埈泰,余東勳,李範熙 成均館大學校 科學技術硏究所 1992 論文集 Vol.43 No.1

In this study 9.5/65/35 PLZT was selected which has the excellent quadratic electro-optic property and slim-loop. It was fabricated by the methods of vacuum hot-pressing and sintering. The electrode of color filter was evaporated using the interdigital type masks. They had the ratio of electrode gaps and the specimen thickness which were 1 : 1, 1.5 : 1, 2 : 1, and 2.5 : 1. Its color filtering characteristics were measured in the range of wavelength 380 to 780[nm] and electric field 0 to 15[kV/cm]. The results shows the relationship between the thickness of specimen, the electrode gap and the maximum RGB transmittance.

통합접지방식의 접지저항 측정방법 개선에 관한 연구

송준태,김재진,방준호,송제호,소병문,유인호 국제차세대융합기술학회 2022 차세대융합기술학회논문지 Vol.6 No.12

In this paper, the limitations and practical improv ement plans of the currently used integrated grounding method earth resistance measurement were presented. According to the potential drop method, it is recommended to separate more than 80m from the earth electrode in consideration of the error rate. B eing more than 80m aw ay from the site is realistically sub j ect to many restrictions. In this paper, in order to check whether the ground resistance value falls within the error range while reducing the separation distance through measurement, an integrated grounding demonstration test facility was first estab lished, a comprehensiv e earth resistance meter, and a multi- function measuring instrument were used to repeatedly measure the earth resistance of aux iliary poles by eq uipment and by distance. T hrough the measurement, it was prov ed that the error range by distance proposed in the potential drop method was w ithin the error range ev en if the current aux iliary electrode was separated by 50M rather than 80M apart, which is the ex isting measurement method. In addition, through analysis of the measurement data, it was confirmed that the ground resistance cannot be measured properly if the ground resistance is measured depending on the aux iliary earth electrode installed in the field in a state where the location of the aux iliary earth electrode installed on the site is unk now n. It was concluded that a partial ex amination was necessary in The results of this paper are ex pected to be used as important basic data for realistic and safe earth resistance measurement in the future. 본 논문에서는 현재 사용되고 있는 통합접지방식 접지저항 측정의 한계 점 및 현실적 개선안 을 제시하였다. 전위강하법에 따르면 오차율을 감안하여 접지극 에서 80m이상 이격을 권고하고 있으나, 현장에서 80m이상 이격하는 것은 현실적으로 많은 제약이 따른다. 본 논문에서는 측정을 통해 이격거리를 줄이면서 접지저항 값이 오차범위 내 들어오는지를 확인하기 위해 먼저 통합접지 실증시험 설비를 구축하였으며, 접지저항을 측정하 는 대표적인 3종류의 장비로써 폭넓게 사용되고 있는 정밀 접지저항계 , 종합접지저항계, 다기능계측기를 활용하여 장비별보조극과 거리별 접지저항을 반복 측정하였다. 측정을 통해 전위강하법에서 제안한 거리별 오차범위를 기존의 측정 방법인 전류보조극을 80m 이격하는 것보다 50m까지 이격하여도 오차범위에 들어왔음을 입증하였다. 또한 측정 데이터 분석을 통해 현장에 설치된 보조접지극의 위치를 알 수 없는 상태에서 기설치된 보조접지극에 의존 하여 접지저항을 측정하 면 제대로 된 접지저항을 측정할 수 없음을 확인하였고, 결국 접지시스템을 검사함에 있어서반드시 부분검사가 필요하다는 결론을 도출하였다. 본 논문의 결과는 향후 현실적이면서 안전한 접지저항 측정에있어서 중요한 기초자료로 활용될 것으로 기대된다.

Analysis of the Dielectric Characteristics of In-Plane-Polarized Ferroelectric Transducers Using Interdigitated Electrodes

송준태,Hyun-Suk Hwang 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.3

The dielectric characteristics of in-plane-polarized feroelectric transducers are analyzed and an equivalent model is suggested. The geometric configuration of feroelectric transducers with interdigitated electrodes (IDE) is symmetricaly simplified and the electric field distribution is analyzed using the finite-element method (FEM). The FEM result shows that the field distribution of the inner feroelectric film between the electrodes is uniform in the in-plane direction and that the eects of the fields in the air and in the inner feroelectric film under the electrodes are negligible. A simplified in-plane equivalent model is derived from the results and the effectiveness of the model is verified by comparing a capacitance value calculated using the model with a simulated result from the FEM analysis and a computation of the energy of the system. The capacitance values are 1.66 and 1.61 pF, respectively. The dielectric characteristics of the fabricated in-plane-polarized lead-zirconate-titanate (PZT) transducers are also tested. The calculated result (3.42 nF) is close to the measured value (3.27 nF).

Characteristics of a NOx Gas Sensor based on a Low-Temperature Co-Fired Ceramic and Ga-Doped ZnO

송준태,Hyun-Suk Hwang,여동훈,신효순,홍연우,김종희,임동건 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.3

For certain applications, the small-size characteristics of MEMS structures can be traded off for low cost production and high manufacturing yields. Low-temperature co-fired ceramic (LTCC) is a more promising material for this application than a silicon substrate. In this work, Ga-doped ZnO (GZO) thin films for gas-sensor applications were deposited on LTCC substrates by using a RF magnetron sputtering method. The LTCC substrates with thicknesses of 400 μm were fabricated by laminating 12 green tapes consisting of alumina and glass particles in an organic binder. The microstructures of the GZO thin films were analyzed by using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). The films were well crystallized in the hexagonal (wurzite) structure and the sensors showed good sensitivity for the NOx gas at a lower operating temperature.

An Analysis of a Microstrip Antenna Using a Quartz Substrate

송준태,강현일 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.2

We theoreticaly investigated the resonant frequency change of a tunable microstrip antenna using a quartz substrate. X-cut, Y-cut and Z-cut quartz microstrip antennas were separately analyzed because of the difference of each cut's piezoelectric properties. The deformation of the antenna was obtained by using a computation of the thicknes strain, extensional strain and shear strain of the quartz substrate. The theoretical results were analyzed and compared with the experimental results. The average erors of the X-cut, Y-cut and Z-cut quartz microstrip antennas were about 1.7 %, 4 % and 5.6 %, respectively. Good agrement betwen the theoretical and the experimental results was obtained.

함정 및 해상무기 연구개발 이야기 (1)

송준태 대한조선학회 2019 大韓造船學會誌 Vol.56 No.1