• Title/Summary/Keyword: Tunable 필터

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Spectral Resolution Enhancement of Acousto-Optic Tunable Filter(AOTF) using Incident Angle Variation (음향광학변조필터의 입사각 변화를 이용한 분해능 향상 방법)

  • You, Jang-Woo;Ahn, Jeong-Ho;Kim, Dae-suk;Kwak, Yoon-Keun;Kim, Soo-Hyun;Lee, Yun-Woo;Whang, In-Duk
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.607-612
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    • 2004
  • Spectral resolution enhancement method of Acousto-Optic Tunable Filter (AOTF) using incident light angle variation is described. AOTF is a small, mechanically rigid, high speed and spectral resolution light tunable filter. The basic theory of AOTF and its experimental verification is described. AOTF can generate two opposite polarized light simultaneously which wavelength can be changed by incident angle variation. We focused on the common region of two filtered light at the specific incident angle. This region can be used to enhance the spectral resolution of AOTF.

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Design of 950~2150MHz tunable bandpass ilter by cascading low and high pass filters (저역 및 고역 통과필터 종속연결형 950~2150MHz 가변대역통과필터의 설계)

  • 신재준;구경헌
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.7
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    • pp.1385-1393
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    • 1997
  • In this paper, a systematic design method of brjoadband tunable bandpass filter is presented by using user defined varactor diode method. The tunable bandpass filter is constructed as the cascade connection of low pass filter and high pass filter. The designed filter shows the characteristeristics of 2.7.+-.0.2dB insertion loss and 37.1.+-.5.0dB insertion loss and 32.1.+-.2.2dB image rejection. The results of the research can be used fodr the broadband tunable filter of DBS tuner and communication instruments.

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Design of A Voltage-controlled Frequency Tunable Integrator and 3rd-order Chebyshev CMOS Current-mode Filter (전압제어 주파수가변 적분기 및 3차 체비세프 CMOS 전류모드 필터 설계)

  • Bang, Jun-Ho;Lee, Woo-Choun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.10
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    • pp.3905-3910
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    • 2010
  • In this paper, a 3rd-order Chebyshev current-mode filter in 1.8V-$0.18{\mu}m$ CMOS parameter is designed. The core circuit of the current-mode filter is composed with the proposed voltage-controlled frequency tunable current-mode integrator. Using the proposed current-mode integrator, the cutoff frequency of the filter can be controlled and also total power consumption can be reduced. HSPICE simulation results show the cutoff frequency of the filter is controlled between 1.2MHz and 10.1MHz, and the power consumption is 2.85mW at Vdd=1.8V.

FBG Sensor Signal Processing System using SLD Tunable Light Source and Etalon Filter (SLD동조 광원과 에탈론 필터를 이용한 FBG 센서 신호처리 시스템)

  • Chung, Chul;Lee, Ho-Joon;Kim, Ki-Soo
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.41 no.3
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    • pp.39-44
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    • 2004
  • Fiber Bragg grating sensors are fabricated by core index modulation using UV laser and phasemask. Bragg wavelength of the grating is changed by the external strain. In this paper, a signal processing system of fiber Bragg grating sensor has studied in the optical wavelength domain. The system is based on the sweep semiconductor light source that consists of SLD, F-P tunable filter and etalon filter. The hysteresis effects of PZT in the F-P tunable filter are compensated. The long term measurement stability is obtained by controlling the temperature of F-P tunable filter and the SLD. We compare the strain data from fiber Bragg grating sensor and that from strain gauge at concrete hume pipe. We also get very good results for the long gauge displacement using fiber Bragg grating sensor which are identical to the data with short gauge length ordinary displacement sensor.

Design of Frequency-Tunable Microstrip Filter Using Triple-Mode Substrate Integrated Waveguide (SIW) Structure (3중모드 기판집적 도파관(SIW) 구조를 이용한 주파수 가변 마이크로스트립 필터 설계)

  • Kyeong-Min Na;Dong-Woo Kim;Soon-soo Oh
    • Journal of IKEEE
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    • v.28 no.1
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    • pp.72-77
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    • 2024
  • In this paper, a triple-mode frequency-tunable filter is proposed to meet the recent demands of various frequency bands of mobile communication services. This filter has a tunable structure that can adjust the resonance frequency using a variable capacitor. To improve the quality factor, a SIW(Substrate Integrated Waveguide) structure was introduced and a structure that induces three resonance modes was implemented through a circular hole located in the center. The change in electric field distribution and resonance frequency by the variable capacitor was simulated using HFSS, and the change in electric field distribution and resonance frequency of Triple Mode mode was confirmed.

Characterization of a Wavelength-Tunable Fiber Laser Based on a Polymer Waveguide Bragg Grating Wavelength Filter (폴리머 도파로 브라그 격자를 이용한 단일 파장 가변 광섬유 레이저의 출력 특성 연구)

  • Choi, Byeong Kwon;Byun, Jong Hyun;Seo, Jun Gyu;Lee, Hak Kyu;Jeon, Min Yong
    • Korean Journal of Optics and Photonics
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    • v.26 no.6
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    • pp.306-311
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    • 2015
  • We report the characteristics of a single-wavelength-tunable fiber laser using a polymer waveguide Bragg grating (PWBG) wavelength filter. The output of the laser depends on environmental conditions, such as temperature and polarization states in the laser cavity. Wavelength tuning can be achieved, about 16.29 nm from 1548.24 nm to 1531.95 nm, according to the electric power applied to the PWBG wavelength filter. The achieved efficiency slope is about -0.16 nm/mW. A side-mode suppression ratio (SMSR) of more than 35 dB can be obtained by adjusting the polarization state in the laser cavity. A stable wavelength-tunable fiber laser can be achieved using the PWBG wavelength filter with a TEC module and a polarization-maintaining fiber.

Frequency-Tunable Bandpass Filter Design Using Active Inductor (능동 인덕터를 이용한 주파수 가변형 대역통과 필터 설계)

  • Lee, Seok-Jin;Choi, Seok-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.7
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    • pp.3425-3430
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    • 2013
  • The fast-growing market in wireless communications has led to the development of multi-standard mobile terminals. In this paper, a frequency-tunable active RC bandpass filter for multi-standards wireless communication system is designed using an active inductor. The conventional bandpass filter design methods employ the high order filter or high quality factor Q to improve the stopband attenuation characteristics and frequency selectivity of the passband. The proposed bandpass filter based on the high Q active inductor has an improved frequency characteristics. The center frequency and gain of the designed bandpass filter is tuned by employing the tuning circuit. We have performed the simulation using TSMC $0.18{\mu}m$ process parameter to analyze the characteristics of the designed active RC bandpass filter. The bandpass filter with Q=20.5 has 90MHz half power bandwidth at the center frequency of 1.86GHz. Moreover, the center frequency of the proposed bandpass filter can be tuned between 1.86~2.38GHz for the multi-standards wireless communication system using the capacitor of the tuning circuit.

The Analysis and Comparison of Tunable Wavelength Filters (파장 가변 필터의 분석 및 비교)

  • Chu, Gwang-Uk;Won, Yong-Hyeop
    • Electronics and Telecommunications Trends
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    • v.11 no.1 s.39
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    • pp.19-27
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    • 1996
  • 파장 가변 필터는 만드는 방법에 따라 특성이 다르기 때문에 시스템의 용도와 목적에 맞는 필터를 선택하기 위해서는 파장 가변 필터에 대한 이해가 필요하다. 이를 위해 본 논문에서는 현재까지 개발된 파장 가변 필터중 실장 가능성이 높은 것의 원리와 장단점에 대하여 분석 및 비교하였고, 현재 상용화된 제품에 대해 정리하였다.

Tunable Single-frequency Er-Doped Fiber Laser Using Acousto-Optic Bandpass Filter (음향광학 대역투과 필터를 사용한 파장가변 단일 주파수 광섬유 레이저)

  • 용재철;이명수;김병윤
    • Proceedings of the Optical Society of Korea Conference
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    • 2001.02a
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    • pp.168-169
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    • 2001
  • 1.55 $\mu\textrm{m}$ 파장 대역에서 동작하는 파장가변 단일 주파수 레이저는 WDM 통신 시스템, 광섬유 센서, 분광학 분야에 유용하게 사용될 수 있다. 특히 어븀첨가 광섬유 레이저로 파장가변 단일 주파수 레이저를 구현하면 선폭이 가늘고, 세기 잡음이 작고, 출력 세기가 크다는 장점이 있기 때문에 많은 연구가 있어 왔다. 본 논문에서는 음향광학 대역투과 필터 (acousto-optic tunable bandpass filter, AOTBF)와 광섬유 흡수 격자를 사용하는 선형공진기 형태의 파장가변 단일 주파수 광섬유 레이저에 대해서 제안하고 구현하였다. (중략)

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