• Title/Summary/Keyword: RF 필터링

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Design of TDD Synchronizer for Wibro RF Repeater (Wibro RF 중계기를 위한 TDD 동기 검출기의 설계)

  • Seo, Young-Ho;Kim, Dong-Wook
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.11A
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    • pp.909-917
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    • 2009
  • In this paper, we proposed and implemented the method to efficiently generate TDD synchronization signal and the digital circuit for the RF repeater which can eliminate the shadow region in the wireless communication field using the time division duplex (TDD) method. After detecting the TDD signal from the transmitted or received RF signal, the detected TDD signal is fed to the RF repeater for the normal operation. The proposed technique detects the envelop of the downlink signal and amplifies the detected envelop, and then restores the degraded envelop with the proposed digital filtering method. Finally the restored envelop is manipulated to the TDD synchronization signal. Our focus on the proposed algorithm is to develop it with simple feature and low cost but robust performance. The proposed scheme was implemented to the integrated system which has both RF and digital circuit and tested under the same condition with the commercial WiBro service.

Design of Edge Manager for Filtering Sensor Tag Data (센서 태그 데이터의 필터링을 위한 Edge Manager의 설계)

  • Lee, Jun-Ho;Ryu, Woo-Seok;Hong, Bong-Hee
    • Proceedings of the Korean Information Science Society Conference
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    • 2008.06c
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    • pp.138-143
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    • 2008
  • RFID 기술은 기존의 바코드 기술보다 발전된 무선의 비접촉 인식 기술로서, 유비쿼터스 컴퓨팅의 핵심기술로 간주되고 있다. RFID 태그는 기존의 단순한 사물의 인식 기능 중심에서 사물의 상태 및 환경 정보를 감지할 수 있는 센서 태그로의 발전으로 물류 프로세스의 양적, 질적 향상을 도모할 수 있게 되었다. 센서 태그는 환경 정보를 센싱하기 위하여 배터리를 내장하고 있으며, RF Transceiver의 내장 유무에 따라 자체적으로 신호를 보낼 수 있는 active 센서 태그와 리더로부터의 신호를 사용하는 semi-passive 센서 태그로 구분된다. Semi-passive 센서 태그는 배터리를 부착함으로써 passive 태그에 비해 인식률과 인식거리가 향상되었고 active 태그에 비해 단가가 매우 저렴하여 센서 태그가 부착된 물품의 상태를 모니터링하고 환경을 감시하는 다양한 응용에 사용될 수 있다. 이러한 응용의 요구에 따라 Edge Manager는 기존의 passive 태그는 물론 센서 태그를 지원함으로써 상위 응용에게 정제된 결과를 전달할 필요성이 있다. 본 논문에서는 특히 semi-passive 센서 태그를 지원하는 Edge Manager의 설계를 위하여, 센서를 사용한 또 다른 활용 분야인 센서 네트워크에서의 질의 유형을 분석하고, semi-passive 센서 태그의 특징을 고려한 요구사항을 분석한다. Semi-passive 센서 태그는 센서 네트워크의 센서 노드와는 달리 태그 레벨에서 필터링과 병합을 수행할 수 없으므로 Edge Manager에서 이러한 기능이 제공되어야 한다. 본 논문에서는 Edge Manager에서의 센서 태그 데이터에 대한 질의를 위한 방법으로 EPCglobal ALE 표준명세의 ECSpec을 확장하는 방법을 제안하고, 센서 태그 데이터의 특성을 고려한 필터링 기법과 병합(aggregation) 기법을 적용한 질의 처리가 가능한 Edge Manager의 구조를 제시한다.

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The Study of ZnO Thin Film for SAW Filter by PLD and RF Magnetron Sputtering (PLD와 RF 마그네트론 스퍼터링을 이용한 SAW 필터용 ZnO 박막의 특성 연구)

  • Lee, Seung-Hwan;Yu, Yun-Sik
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.25 no.12
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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.

A Study on the ZnO Piezoelectric Thin Films for SAW Filter by RF Magnetron Sputtering (RF 마그네트론 스퍼터링에 의한 SAW 필터용 ZnO 압전 박막에 관한 연구)

  • 최형욱;김경환;김상종;강종윤;안병국;윤석진
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.9
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    • pp.798-807
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    • 2002
  • ZnO thin films on Si wafer were deposited by RF magnetron reactive sputter with various RF power, chamber pressure, argon/oxygen gas ratios ana substrate temperatures. Crystallinities, surface morphologies, and electrical properties of the films were investigated by XRD, AFM, RBS, and electrometer(keithley 617). ZnO films showed a strong c-axis preferred orientation. Surface roughness and resistivity were changed by the argon/oxygen gas ratio. The minimum surface roughness of 12${\AA}$ and maximum resistivity of $10^8\Omega cm$ were achieved at Ar/O$O_2$=0/100.

Piezoelectric Thin Film of Electrical Sensor Filter for Security System (기계경비용 전기센서필터의 압전박막 특성)

  • Lee, Dong-Yoon
    • Proceedings of the Korea Contents Association Conference
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    • 2008.05a
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    • pp.595-597
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    • 2008
  • Zinc Oxide(ZnO) thin films on Si (100) substrate were deposited by RF magnetron sputter with changing sputtering conditions such as argon/oxygen gas ratios, RF power, and substrate temperature, chamber pressure and target-substrate distance. To analyze a crystallographic properties of the films, ${\Theta}/2{\Theta}$ mode X-ray diffraction, SEM analyses. C-axis preferred orientation highly depended on RF power.

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Coupling Matrix Synthesis Methods for RF/Microwave Filter Design (초고주파용 필터설계를 위한 결합행렬 합성법)

  • Choi, Dong-Muk;Kim, Che-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.12A
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    • pp.1346-1353
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    • 2007
  • In this paper, the methods are presented for the calculation of general coupling coefficient matrixes used in the band pass filter design. They are calculated from transmission coefficient($S_{21}$) and reflection coefficient($S_{11}$) with desired characteristics derived from the poles of filter function and return loss(RL). The calculated matrixes from this method are transformed to the folded canonical filter structure using similarity transformation which lends us the practical filter design. Based on the resulting matrix, the folded canonical filter has been designed.

A Study on the ZnO Thin Film SAW Filter by RF Sputter (RF 마그네트론 스퍼터링에 의한 ZnO 박막 SAW 필터에 관한 연구)

  • 박용욱;신형용;박정흠;강종윤;심성훈;최지원;윤석진;김현재;김경환
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.6
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    • pp.481-486
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    • 2001
  • ZnO thin films on glass substrate were depostied by RF magnetron reactive sputter with various argon/oxygen gas ratios and substrate temperatures. Crystallinities, surface morphologies, chemical compositions, and electrical properties of the films were investigated by XRD, SEM, XPS and electrometer(keithley 617). All films showed a strong preferred orientation along the c-axis on glass substrate, and the chemical stoichiometry was obtained at Ar/O$_2$.=50/50. The propagation velocity of ZnO SAW filter was about 2,590 m/sec and insertion loss was a minimum value of abut -21dB.

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A Study on the ZnG Thin Film SAW filter by RF Sputter (RF 마그네트론 스퍼터링에 의한 ZnO 박막 SAW 필터에 관한 연구)

  • 박용욱;이동윤;백동수;윤석진;김현재;박창엽
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.11a
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    • pp.151-154
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    • 1999
  • ZnO thin films on glass substrate were deposited by RF magnetron reactive sputter with various argodoxygen gas ratios and substrate temperatures. Crystallinities, surface morphologies, chemical compositions, and electrical properties of the films were investigated by XRD, SEM, XPS and electrometer(keith1ey 617). All films showed a strong prefered orientation along the c-axis on glass substrate, and the chemical stoichiometry was obtained at Ar/$O_2$=50/50. The propagation velocity of ZnO SAW filter was about 2, 590 dsec and insertion loss was a minimum value of about -21dB.

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Design of a Compact GPS/MEMS IMU Integrated Navigation Receiver Module for High Dynamic Environment (고기동 환경에 적용 가능한 소형 GPS/MEMS IMU 통합항법 수신모듈 설계)

  • Jeong, Koo-yong;Park, Dae-young;Kim, Seong-min;Lee, Jong-hyuk
    • Journal of Advanced Navigation Technology
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    • v.25 no.1
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    • pp.68-77
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    • 2021
  • In this paper, a GPS/MEMS IMU integrated navigation receiver module capable of operating in a high dynamic environment is designed and fabricated, and the results is confirmed. The designed module is composed of RF receiver unit, inertial measurement unit, signal processing unit, correlator, and navigation S/W. The RF receiver performs the functions of low noise amplification, frequency conversion, filtering, and automatic gain control. The inertial measurement unit collects measurement data from a MEMS class IMU applied with a 3-axis gyroscope, accelerometer, and geomagnetic sensor. In addition, it provides an interface to transmit to the navigation S/W. The signal processing unit and the correlator is implemented with FPGA logic to perform filtering and corrrelation value calculation. Navigation S/W is implemented using the internal CPU of the FPGA. The size of the manufactured module is 95.0×85.0×.12.5mm, the weight is 110g, and the navigation accuracy performance within the specification is confirmed in an environment of 1200m/s and acceleration of 10g.

Design and Fabrication of Miniaturized Dual-bandpass filter Using Rectangular ring resonator and Interdigital capacitive feeding-structure (Rectangular Ring 공진기와 Interdigital Capacitive 급전구조를 이용한 소형화된 이중대역통과필터의 설계 및 제작)

  • Yoon, Hyun-Soo;Kang, Sang-Rok;Choi, Byoung-Ha
    • Journal of Navigation and Port Research
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    • v.31 no.5 s.121
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    • pp.415-420
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    • 2007
  • In this paper, we have designed and fabricated a new type of bandpass-filter that used rectangular ring and interdigital capacitive feeding-structure. The filter is applied the modified rectangular ring and interdigital capacitive feeding-structure in patch, which reduce rho size of filter and IEEE 802. 11 correspond to wireless LAN domain(2.45GHz and 5.2GHz) for operating. As a result, the design and fabrication process of the filter become simple and the size of it is reduced more than 60% compared with RF filter are available conventional PEMBF(Parallel Edge-coupled Microstrip Bandpass Filter) of accounted circuit by minimum stage, measurement result of fabricated filter, center frequence is down 2.408GHz and 5.075GHz. input return loss is -39.169dB at 2.408GHz, -40.922dB at 5.075GHz. insertion loss is -0.437dB at 2.408GHz, -1.669dB at 5.075GHz.