Ti3O5/SiO2 다층박막를 이용한 협대역 칼라투과필터제작 및 특성연구

박문찬,고견채,이화자 한국안광학회 2011 한국안광학회지 Vol.16 No.4

Purpose: The narrow-band pass color-filters with a 500 nm central wavelength and 12 nm FWHM using Ti3O5/ SiO2 mutilayer were fabricated, and their characteristics and structures were studied. Methods: the optical constants, n and k, of the Ti3O5 and SiO2 thin films were obtained from the transmittances of their thin film. The narrow-band pass color-filters were designed with these optical constants and the AR coating of the filter was also designed. Ti3O5/SiO2 multilayer filters were made by electron beam evaporation apparatus and the transmittaces of the filters were measured by spectrophotometer. the number of layers and the thicknesses of filters were calculated from the cross section of filters by SEM image and the composition of filters was analysed by XPS analysis. Results: The optimization of AR coating for the narrow-band pass color-filter was [air|SiO2(90)| Ti3O5(36)|SiO2(5)| Ti3O5(73)| SiO2(30)|Ti3O5(15)|glass], and the optimization of filter layer for the color filter was [air|SiO2(192)|Ti3O5(64)|SiO2(102)|Ti3O5(66)|SiO2(112)|Ti3O5(74)|SiO2(120)|Ti3O5(68)|SiO2(123)|Ti3O5(80)|SiO2(109)| Ti3O5(70)|SiO2(105)|Ti3O5(62)|SiO2(99)|Ti3O5(63)|SiO2(98)|Ti3O5(51)|SiO2(60)|Ti3O5(42)|SiO2(113)|Ti3O5(88)|SiO2(116)| Ti3O5(68)|SiO2(89)|Ti3O5(49)|SiO2(77)|Ti3O5(48)|SiO2(84)|Ti3O5(51)|SiO2(85)|Ti3O5(48)|SiO2(59)|Ti3O5(34)|SiO2(71)| Ti3O5(44)|SiO2(65)| Ti3O5(45)| SiO2(81)| Ti3O5(52)|SiO2(88)| glass]. It was known that the color-filters fabricated by the simulation data were composed of 41 layers by SEM image and the top layer of filters was SiO2 layer and the filters were composed of SiO2/Ti3O5 multilayer by XPS analysis. It was also known that the mixed thin film of TiO2 and Ti3O5 was made during the deposition of the Ti3O5 material. Conclusions: The narrow-band pass color-filters with a 500 nm central wavelength and 12 nm FWHM using Ti3O5/SiO2 mutilayer of 41 layer were fabricated, and it was known that the mixed form of TiO2 and Ti3O5 thin film was made during the deposition of the Ti3O5 material. 목적: Ti3O5와 SiO2를 이용하여 중심파장이 500 nm에서 반치폭이 약 12 nm이고 투과율이 99%인 협대역 칼라투 과필터를 제작하고, 이 칼라필터의 박막 특성을 연구하고자 한다. 방법: 두께 800 nm인 Ti3O5박막과 SiO2박막의 투 과율로부터 박막의 광학상수 n(굴절률)과 k(소멸계수)를 구하였고, Essential Macleod program을 이용하여 중심파장 이 500 nm에서 반치폭이 약 12 nm이고 투과율이 99%인 협대역 칼라투과필터의 필터층과 AR 코팅층을 설계하였다. 또 한 electron beam evaporation 장치를 이용하여 Ti3O5/SiO2 다층막 칼라필터을 만든 후, 분광광도계를 이용하여 투과율 을 측정하였고, SEM 사진에 의한 칼라필터의 단면으로부터 칼라필터의 박막두께와 층수를 알 수 있었고, XPS분석으 로부터 박막 성분을 분석하였다. 결과: 칼라필터의 AR 코팅층의 최적조건은 6층으로 [air|SiO2(90)|Ti3O5(36)|SiO2(5)| Ti3O5(73)| SiO2(30)|Ti3O5(15)|glass]이며, 반치폭이 12 nm인 칼라필터의 필터층의 최적조건은 41층으로 [air |SiO2(20)|Ti3O5(64)|SiO2(102)|Ti3O5(66)|SiO2(112)|Ti3O5(74)|SiO2(120)|Ti3O5(68)|SiO2(123)|Ti3O5(80)|SiO2(109)| Ti3O5(70)|SiO2(105)|Ti3O5(62)|SiO2(99)|Ti3O5(63)|SiO2(98)|Ti3O5(51)|SiO2(60)|Ti3O5(42)|SiO2(113)|Ti3O5(88)| SiO2(116)|Ti3O5(68)|SiO2(89)|Ti3O5(49)|SiO2(77)|Ti3O5(48)| SiO2(84)|Ti3O5(51)|SiO2(85)|Ti3O5(48)|SiO2(59)| Ti3O5(34)|SiO2(71)|Ti3O5(44)|SiO2(65)|Ti3O5(45)| SiO2(81)|Ti3O5(52)| SiO2(88)| glass] 이었다. 위의 데이터를 이용하여 제작한 칼라필터는 SEM 사진에 의해 41층으로 확인되었으며, XPS 분석에 의해 SiO2층이 맨 위층이며 Ti3O5층과 교번인 다층막으로 형성돼 있으며, Ti3O5박막 형성 시 TiO2 박막과 Ti3O5박막이 섞여 형성됨을 알 수 있었다. 결론: 41층의 Ti3O5/SiO2 다층박막을 이용하여 12 nm 반치폭을 갖으며 500 nm 중심파장에서 투과율은 99%인 협대역 칼라투 과필터를 제작하였으며, 이 칼라필터는 Ti3O5박막 형성 시 TiO2 박막과 Ti3O5박막이 섞여 형성됨을 알 수 있었다.

LTCC 공정 기술 기반 협대역 결합 공진기 필터

조학래(Hak-Rae Cho),서수덕(Soo-Duk Seo),구경헌(Kyung Heon Koo) 대한전자공학회 2019 전자공학회논문지 Vol.56 No.5

본 논문에서는 비교적 낮은 유전율을 갖는 LTCC 소재를 이용하여 비대역폭 3% 이하인 5차 협대역 필터를 설계하였다. 협대역 필터의 기능과 성능을 개선하기 위하여 교차결합 원리를 적용하여 인접대역의 차단 특성을 향상시켰다. 높은 차단과 낮은 삽입손실 특성은 서로 인접하지 않은 공진기 간에 결합 구조를 추가하여 얻었다. 필터를 구성하는 결합공진기 사이에 전자기 교차 결합 구조를 갖는 작은 스트립선로 패치를 추가하여, 공진기 차수를 감소시키고 차단 특성을 개선할 수 있는 LTCC 대역통과 필터가 구현되었다. 제작 과정에 있어서 NH20M4 유전체 파우더를 사용한 LTCC 필터 구조 내에 Namics의 7251S 전극을 2겹으로 인쇄함으로써 최상의 필터 특성을 얻었다. 이 경우, 설계에 사용된 매체의 유전율은 21.5이며, 구현된 크기는 0.8㎓ 대역에서 6×5×3 [㎣]이다. This paper has presented the design of a narrow band filter with less than 3% bandwidth and the filter order of 5, using a relatively low permittivity LTCC material. The cross-coupling principle is applied to improve the function and performance of the narrow band filter, and the blocking characteristics of the adjacent band have been enhanced. High blocking and low insertion loss characteristics are obtained by adding coupling structures between resonators that are not adjacent to each other. By adding a small strip line patch with an electromagnetic cross-coupling structure between the coupled resonators constituting the filter, the LTCC band pass filter is realized which can reduce the resonator-order and improve the blocking characteristics. In the fabrication process, Namics’ 7251S electrode was printed twice in the LTCC filter structure using NH20M4 dielectric powder, and the best filter characteristics have been obtained. In this case, the dielectric constant of the material used in the design is 21.5, and the implemented size is 6×5×3 [㎣] for the 0.8 ㎓ band.

A Dual-Mode Narrow-Band Channel Filter and Group-Delay Equalizer for a Ka-Band Satellite Transponder

SungtekKahng,이성팔,ManSeokUhm 한국전자통신연구원 2003 ETRI Journal Vol.25 No.5

This paper presents the design of a narrow-band channel filter and its group-delay equalizer for a Ka-band satellite transponder. We used an 8th order channel filter for high selectivity with an elliptic-integral function response and an inline configuration. We designed a 2-pole, reflection-type, group-delay equalizer to compensate for the steep variation of the group-delay at the output of the channel filter, keeping the thermal stability at ±7 ns of group-delay variation at the band edges over 15–55 °C. We devised a new tuning technique using short-ended dummy cavities and used it for tuning both the filter and equalizer; this removes the necessity of additional tuning after the cavities are assembled. Through measurement, we demonstrate that the group-delay-equalized filter meets the equipment requirements and is appropriate for satellite input multiplexers.

굴절체를 이용하여 감지 사각 문제를 개선한 협대역 마일즈 감지 시스템

기현철 大韓電子工學會 2012 電子工學會論文誌-SD (Semiconductor and devices) Vol.49 No.7

본 논문에서는 협대역 간섭 광학 필터(narrow band interference optical filter)를 적용하여 광학적 잡음에 내성이 강한 차세대용 마일즈 감지 시스템을 구현하고자 시도하였다. 900㎚의 레이저 파장에 대해 파장범위(wavelength range) 895~915㎚의 협대역 간섭 광학 필터를 적용한 결과 시가전 상황에서 발생할 수 있는 강한 광학적 잡음에 내성을 갖는 감지 특성을 얻을 수 있었다. 그러나 청색천이(blue shift) 현상에 의해 마일즈 감지 시스템에 입사각 30º~90º 구간에 감지 사각 영역이 발생하였다. 이 문제를 해결하기위해 굴절체를 이용한 입사각 산란 방법을 제안하였고, 디옵터 5.4의 오목 메니스커스 렌즈 굴절체(concave meniscus lens refractor)를 마일즈 감지 시스템에 적용하여 입사각을 산란시킨 결과 감지 사각을 없앨 수 있었다. In this paper, we tried to realize a next generation MILES detection system which is robust to optical noise using a narrow band interference optical filter. Applying a narrow band interference optical filter which has the wavelength range of 895~915㎚ to the LASER wavelength of 900㎚, we could obtain detection characteristics robust to strong optical noise which can be occurred in street battles. However, the MILES detection system has the blind range of detection in the incident angle range of 30º~90º. To solve this problem we proposed a method of incident angle scatter using refractors. Applying a concave meniscus lens refractor which has diopter of 5.4 to the MILES detection system, we could eliminate the blind angle of detection.

레이더 신호 탐지용 디지털수신기 개발

차민연,최혁재,김성훈,문병진,김재윤,이종현 한국군사과학기술학회 2019 한국군사과학기술학회지 Vol.22 No.3

Electronic warfare systems are needed to be advantageous in the modern war. Many radar threat signals with various frequency spectrums and complicated techniques exist. For detecting the threats, a receiver with wide and narrow-band digital processing is needed. To process a wide-band searching mode, a polyphase filter bank has become the architecture of choice to efficiently detect threats. A polyphase N-path filter aligns the re-sampled time series in each path, and a discrete Fourier transform aligns phase and separates the sub-channel baseband aliases. Multiple threats and CW are detected or rejected when the signals are received in different sub-channels. And also, to process a narrow-band precision mode, a direct down converter is needed to reduce aliasing by using a decimation filter. These digital logics are designed in a FPGA. This paper shows how to design and develop a wide and narrow-band digital receiver that is capable to detect the threats.

ITS용 5.8 GHz 스터브 위치를 이용한 협대역 대역통과 여파기 설계

윤기철,이일우,한승현,장팡,권성수,박정근,윤태순,이종철 한국ITS학회 2006 한국ITS학회 학술대회 Vol.2006 No.1

Optimization of Cancellation Path Model in Filtered-X LMS for Narrow Band Noise Suppression

Kim, Hyoun-Suk,Park, Youngjin Institute of Control 1999 Transaction on control, automation and systems eng Vol.1 No.1

Adaptive algorithms based on gradient adaptation have been extensively investigated and successfully joined with active noise/vibration control applications. The Filtered-X LMS algorithm became one of the basic feedforward algorithms in such applications, but is not fully understood yet. Effects of cancellation path model on the Filtered-X LMS algorithm have investigated and some useful properties related to stability were discovered. Most of the results stated that the error in the cancellation path model is undesirable to the Filtered X LMS. However, we started convergence analysis of Filtered-X LMS based on the assumption that erroneous model does not always degrade its performance. In this paper, we present a way of optimizing the cancellation path modern in order to enhance the convergence speed by introducing intentional phase error. Carefully designed intentional phase error enhances the convergence speed of the Filtered X LMS algorithm for pure tone noise suppression application without any performance loss at steady state.

Optical Humidity Sensor Using a Narrow Band-Pass Filter Prepared by Glancing Angle Deposition

황보창권,Dae-Ho Chang,박용준 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5

This paper reports a study of an optical humidity sensor which gives a sensible response to various humidity conditions. The optical humidity sensor can be obtained through nanoscale porosity variations produced by using a physical vapor deposition technique known as glancing angle deposition (GLAD). The optical humidity sensor made of narrow band-pass filter (NBPF) is fabricated by the GLAD technique. The transmittance spectrum of this sensor shifts due to a change in the effective refractive index of the porous microstructure, resulting from water-vapor adsorption/desorption at various humidity conditions. The sensitivity, the hysteresis and the response time properties of the sensor are also studied.

Nano-gap Control Algorithm for Solid Immersion Lens High-Speed Noncontact Near-Field Optical Scanning System

Jung-Gon Kim 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.춘계 No.-

This paper aims to improve the robustness of the nano-gap control algorithm for a solid immersion lens (SIL)-based near-field (NF) optical scanning system against dynamic disturbances, such as external shocks and vibrations. The robust control system is essential in high-speed noncontact NF optical system because the nanoscale gap distance between the SIL and the media is 20 ㎚ or less. Thus, we propose and improved nano-gap control system with a narrow-band disturbance filter (NBDF) using the internal model principle (IMP), which is an effective control method for enhancing the performance of the system for the rejection of repeatable and nonrepeatable disturbances. Moreover, we will demonstrate improved control performance in the NBDF with a double disturbance observer (DOB) upon receiving repeatable and nonrepeatable disturbances.

Empirical mode decomposition based on Fourier transform and band-pass filter

Chen, Zheng-Shou,Rhee, Shin Hyung,Liu, Gui-Lin The Society of Naval Architects of Korea 2019 International Journal of Naval Architecture and Oc Vol.11 No.2

A novel empirical mode decomposition strategy based on Fourier transform and band-pass filter techniques, contributing to efficient instantaneous vibration analyses, is developed in this study. Two key improvements are proposed. The first is associated with the adoption of a band-pass filter technique for intrinsic mode function sifting. The primary characteristic of decomposed components is that their bandwidths do not overlap in the frequency domain. The second improvement concerns an attempt to design narrowband constraints as the essential requirements for intrinsic mode function to make it physically meaningful. Because all decomposed components are generated with respect to their intrinsic narrow bandwidth and strict sifting from high to low frequencies successively, they are orthogonal to each other and are thus suitable for an instantaneous frequency analysis. The direct Hilbert spectrum is employed to illustrate the instantaneous time-frequency-energy distribution. Commendable agreement between the illustrations of the proposed direct Hilbert spectrum and the traditional Fourier spectrum was observed. This method provides robust identifications of vibration modes embedded in vibration processes, deemed to be an efficient means to obtain valuable instantaneous information.