• 한국광학회:학술대회논문집
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• 한국광학회 1991년도 제6회 파동 및 레이저 학술발표회 Prodeedings of 6th Conference on Waves and Lasers
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• pp.98-101
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• 1991

The As2S3 thin film has a characteristics of optical modulation in both amplitude and phase. Since the As2S3 thin film can be used as a real-time reconfigurable optical filter, the fSDF filter can be optically fabricated on it. According to the modulation characteristics of the As2S3, the optimal fSDF filter recorded on this thin plate has the form of continuous amplitude and binary phase. Computer simulation and optical experiments on the optical pattern classification show that the As2S3 is suitable for the optical fSDF filter.

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권4호
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• pp.176-179
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• 2005

The increasing demand for high density packaging technologies and the evolution to mixed digital and analogue devices has been the con-set of increasing research in thin film multi-layer technologies such as the passive components integration technology. In this paper, Cu and TaO thin film with RF sputtering was deposited for spiral inductor and MOM capacitor on the $SiO_2$/Si(100) substrate. MOM capacitor and spiral inductor were fabricated for L-C band pass filter by sputtering and lift-off. We are analyzed and designed thin films L-C passive components for band pass filter at 900 MHz and 1.8 GHz, important devices for mobile communication system. Based on the high-Q values of passive components, MOM capacitor and spiral inductors for L-C band pass filter, a low insertion loss of L-C passive components can be realized with a minimized chip area. The insertion loss was 3 dB for a 1.8 GHz filter, and 5 dB for a 900 MHz filter. This paper also discusses a analysis and practical design to thin-film L-C band pass filter.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 추계학술대회 논문집 학회본부
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• pp.653-655
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• 1997

In this paper, a monoblock dielectric filter for 900MHz band CT-1 is designed by using CAD(Computer Aided Design). Equivalent circuit for monoblock dielectric filter represented by parallel coupled stripline is simulated by using SuperCompact software tool. A Designed filter structure is simulated by using HFSS to optimize result.

• 한국전기전자재료학회논문지
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• 제25권12호
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• pp.979-983
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• 2012

We proposed the ZnO thin film for a SAW filter by PLD and RF sputtering method. ZnO thin films was pre-deposited on a sapphire substrate as a seed layer by PLD method and then deposited on seed layer by RF sputtering. The surface characteristics of ZnO thin film were investigated by XRD, SEM and AFM. The minimum surface roughness was 1.92 nm and FWHM of rocking curve was $0.92^{\circ}$. We demonstrated the SAW filter with bandwidth of approximately 0.97 MHz and the center frequency of 18.72 MHz using the proposed ZnO thin film.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.131.1-131.1
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• 2005

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1996년도 추계학술대회 논문집
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• pp.389-392
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• 1996

The recent development of high temperature superconducting epitaxial thin film offer great potential for planar passive microwave application such as ring resonator, filters, transmission lines, and antennas. This paper describes the fundamental properties of Microstrip Band-Pass Filter using HTS Thin Film and its application to microwave devices. In order to fabricate HTS microstrip multiple filters, We have grown laser ablated HTS thin films, patterned by photolithographic process and wet etching processes intro HTS microwave devices.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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• pp.141-144
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• 2003

This study proposes ZnO thin film as a piezoelectric material for SAW (surface acoustic wave) filter. The ZnO thin film with thickness $2.6{\mu}m$ was deposited (0001)-oriented sapphire by RF magnetron sputtering technique. IDTs (inter-digital transducers) electrodes were patterned upon SAW filter mask with solid finger structure unapodized using lift-off method on ZnO piezoelectric thin film. SAW propagation velocity was measured with the center frequency by HP 8753C network analyzer. A fabricated ZnO SAW filter exhibited a high propagation velocity of 5433 $^m/s$ and relatively insertion loss of -53.391dB at $\lambda=80{\mu}m$. The side-lobe attenuation of the center frequency was about 17dB. When the wavelength was $80{\mu}m$ $(\lambda/4=20{\mu}m)$, the center frequency was 67.907 MHz. $k^2$ (electromechanical coupling coefficient) was 15.84 %.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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• pp.759-762
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• 2003

The epitaxially grown Mg-doped GaN thin film was prepared by MOCVD (Metal Organic Chemical Vapor Deposition) for a SAW(Surface Acoustic Wave) filter. Mg-doped GaN thin film had enough properties for a SAW filter which include crystallinity and morphology. The surface morphology and crystalline of the Mg-doped GaN thin films were characterized using AFM and an X-ray rocking curve. The SAW filter, which was fabricated by lift-off process and frequency response, was measured by HP 8753C network analyzer. Center frequency was 96.687 MHz and SAW velocity was 5801 m/s when wavelength(λ) was 60${\mu}{\textrm}{m}$. Insertion loss was over -10 dB, Q was factor over 200, and side lobe attenuation was over 22 dB which was suitable for use as a SAW filter. Electro-mechanical coupling coefficient (k$^2$) was calculated from the measured data. k$^2$ was from 1 % to 1.44 %. The fabricated SAW filter using Mg-doped GaN/sapphire structure has good qualities as a filter and will be used as a SAW filter for operating RF frequency.

• 한국광학회지
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• 제14권3호
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• pp.306-311
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• 2003

본 논문에서는 광전송시스템에서 파장분할다중화 광소자로 사용되는 박막필터형 광소자의 특성 분석 및 평가를 위해 입력광원을 모델링 하였으며 광경로에 대해 광선추적법을 사용하여 전산모의 한 광특성을 실험과 비교, 분석하였다. 그 결과 입력광원에 대한 cell 방식의 모델링이 결합효율의 정확도 및 가우시안 강도분포에 접근성을 볼 때 마이크로 옵틱스형 광소자 분석함에 있어 적합함을 알 수 있다. 박막필터형 광소자에 대한 최적 전산모의 결과 광섬유와 GRIN 렌즈 사이 거리가 0.24mm이며 GRIN 렌즈와 박막필터 사이 거리가 0.25mm일 때 최대 결합효율은 -0.11 ㏈이었으며 동일한 조건에의 실험결과 -0.35 ㏈의 최대 결합효율을 얻었다. 이것은 단심 및 이심페룰, GRIN 렌즈 등과 같은 구성품의 불완전성과 박막필터에 의한 손실을 고려할 때, 전산모의 결과와 매우 일치하는 것으로서 본 연구에서 제안한 입력광원의 모델링을 적용한 전산모의가 박막필터형 광소자의 특성을 예측할 수 있음을 보였다.

• 한국전기전자재료학회논문지
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• 제14권5호
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• pp.435-443
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• 2001

As power durable RF SAW filters, AL-(0∼2wt%)Cu alloy multi-layered thin electrodes were deposited on 42° LiTaO$_3$ piezoelectric substrates by magnetron sputtering process, and then ladder-type RF SAW filters, satisfying the electrical specification of CDMA transmission band, were fabricated through optimizing SAW resonator structures. The temperature of film electrodes in SAW filter was increased with RF power, and reached the maxima to cause a failure of SAW filters at the cut-off frequencies of the RF filter band. As RF power increases, the electrodes of Al-Cu alloy showed higher power durability than that of pure Al. The multi-layer laminated film of Al-1wt.% Cu/Cu/Al-1wt%Cu resulted in the best power durability up to 4W of RF power. Every film electrode, however, was destroyed within seconds whenever applying a critical RF power to SAW filters, regardless of the composition and structure of film electrodes. The breakdown of film electrodes under FR power seems to believe due to the fatigue of electrodes caused by repetitive cyclic stress of surface acoustic wave, which is amplified as RF power increases.