• 제목/요약/키워드: Phased Array System

검색결과 159건 처리시간 0.033초

X-대역 2차원 위상배열안테나 빔조향 시스템 개발 (The Development of a Beam Steering System for X-band 2-D Phased Array Antenna)

  • 김두수
    • 한국군사과학기술학회지
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    • 제11권4호
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    • pp.92-98
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    • 2008
  • A beam steering system of X-band 2-D phased array antenna for radar application is developed. The beam steering system consists of real-time command generator, beam steering unit, control PCB of array module and power supply. It plays a role of beam steering and on-line check of phased array antenna. The performance of beam steering system is verified with pulse timing of current control in phase shifters and measurement of far-field of phased array antenna. The developed beam steering system offers basic technology to develop full-scale beam steering system of multi-function radar.

슬롯라인 결합을 이용한 능동 위상배열안테나에 관한 연구 (A study on the active phased array antennas with slotline coupling)

  • 문철;김선택;윤영중;박한규
    • 한국통신학회논문지
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    • 제22권5호
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    • pp.981-989
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    • 1997
  • In this paper, the 5-element active phased array antennas coupled through slotline between elements are designed and fabricated. A recent studies on the active phased array antennas using the transmission line coupling which can be designed to provide strong coupling and the appropriate coupling phase. But this sturucture has limitation of expanding in two dimensions for planar active phased array antennas and distortion of the radiation pattern caused by coupling network. Thus our work proposes the slotline coupling structure asthe broadband coupling network for the active phased array antenna. In experiment, 5-elements active phased array antenas have steering range from -30.deg. to 20.deg. off broadside as the free-running frequencies of end elements are controlled. The overall results show that the proposed slotline coupling structure is suited for the coupling network in the actie phased array antenna system. And the proposed coupling structire solves the expansion problem and eliminates the distortion of the radiation pattern caused by the spurious radiation of the transmission line coupling network. Thus thiscan be expanded to two dimensional coupling network for the planar active phased array antenna system.

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Improvement of Noise Performance in Phased-Array Receivers

  • Kim, Jung-Hyun;Jeong, Jin-Ho;Jeon, Sang-Geun
    • ETRI Journal
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    • 제33권2호
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    • pp.176-183
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    • 2011
  • This paper presents a new analytical approach and experimental verification for the improvement of noise performance in phased-array receivers. For analysis purposes, a multi-channel array system is converted into an equivalent single-channel system, such that the two presents the identical signal and noise powers at the output, respectively. We define an effective gain, noise figure, and signal-to-noise ratio in the equivalent system. Through the proposed approach, the noise performance of the array receiver is analyzed in a general and straightforward manner and then compared to that of each individual array channel. In addition, the phase noise of the array system is analyzed in a rigorous manner, showing its effective reduction by a factor of the array size. The predicted improvement of the noise performance is experimentally confirmed with a CMOS integrated phased-array receiver.

평판 구조물의 영상화를 위한 위상 배열 시스템 개발 및 응용 (Development and Application of Phased Array System for Defect Imaging in Plate-like Structures)

  • 이주경;권영의;이흥선;승홍민;김기연;이준규;김회웅;이호철;김윤영
    • 한국소음진동공학회논문집
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    • 제24권2호
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    • pp.123-130
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    • 2014
  • An ultrasonic magnetostrictive transducer-based phased-array system for imaging defects in plate structures is newly proposed. In that most ultrasonic phased array systems rely on piezoelectric transducers or electromagnetic acoustic transducers, this system has its own unique feature of employing magnetostrictive transducers. Interest in using a phased array system using magnetostrictive transducers has been recently reported for pipe inspection but no such system has been developed for plate inspection. In this investigation, we aim to propose a phased array system using OL-MPTs (Omnidirectional Lamb wave Magnetostrictive Patch Transducers) for plate inspection. The developed system consists of a multi-channel function generator, power amplifiers, preamplifiers and a data acquisition unit. In the process of its development, each of the units must be checked and in doing so, we suggest types of ultrasonic wave experiments that should be carried out. Finally, the phased system using a transducer array composed of eight OL-MPTs is newly configured and is applied for actual crack detection experiments.

위상배열 탐상검사법을 이용한 풍력발전용 블레이드의 일정가압 메커니즘 신뢰성 평가 (Reliability Evaluation of Constant Pressure Mechanism on Phased Array Ultrasonic Testing for Wind Turbine Blade)

  • 남문호;지수정;임선;임승환;정예찬
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제17권3호
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    • pp.236-245
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    • 2017
  • Purpose: There is no established inspection system for composite wind blade during the fabrication stage even though the blades are one of the most important part at wind generation system, but phased array ultrasonic testing method has been continuously studied about wind turbine blade with composite. When wind turbine blade with complex shape by phased array probe is inspected, it is necessary to study for system keeping constant pressure using pressure device. Methods: In this paper, we propose constant pressure device for inspecting wind turbine blade by phased array ultrasonic test method. Design of the device controller is based on Hunt-Crossley model. We evaluate reliability of phased array ultrasonic inspection result that applicated constant pressure device. Result: Defect indication is precise and its error is small when constant pressure mechanism based on Hunt-Crossley model was used. Conclusion: When inspection is progressed using constant pressure mechanism, the reliability of composite wind blade inspection can be improved.

자기변형 트랜스듀서의 위상차를 이용한 평판에서의 Lamb파 집속 기초 실험 (Basic Experiment for Lamb Wave Focusing by Phased Magnetostrictive Transducers in a Plate)

  • 이주경;김회웅;이호철;김윤영
    • 한국소음진동공학회논문집
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    • 제21권3호
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    • pp.227-233
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    • 2011
  • The ultrasonic guided wave phased array using magnetostrictive patch transducers is proposed. The magnetostrictive transducer has received much attention because it is cost-effective and capable to generate ultrasonic waves with a simple configuration. However, it has not been used for ultrasonic guided wave phased array applications until now. In this paper, we propose a magnetostrictive transducer based phased array system consisting of a multi-channel function generator, power amplifiers and Lamb wave magnetostrictive transducers. To check the performance of the ultrasonic guided wave phased array, several Lamb wave focusing experiments were carried out in an aluminum plate. The results demonstrated the capability of the developed array to focus the Lamb waves at specific target points.

능동 위상 배열 안테나의 반사 특성을 고려한 안정적 시스템 운용에 관한 연구 (A Study on the Stabilized System Operation Considering the Reflection Characteristic of an Active-Phased Array Antenna)

  • 김영완;채희덕;이동국;정명득;박종국
    • 한국전자파학회논문지
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    • 제23권1호
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    • pp.29-37
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    • 2012
  • 본 논문에서는 능동 위상 배열 안테나(APAA: Active-Phased Array Antenna)의 능동 반사 계수(ARC: Active Reflection Coefficient) 개선 및 보호 회로 구성을 통한 안정적인 시스템 운용에 관하여 연구하였다. 수동 위상배열 안테나에서와 달리 APAA는 복사 소자와 송수신 모듈이 결합된 형태로 일반적인 수동 위상 배열 안테나의 반사 계수 특성과 차별된 새로운 ARC의 정의가 적용되어야 한다. ARC는 방사하는 소자로부터의 자기 반사계수 외에 인접한 방사 소자로부터 유기되는 결합량의 중첩을 고려한 반사 계수이다. 이는 능동 위상 배열 레이더(APAR: Active-Phased Array Radar) 시스템의 특성을 예측하고 분석하는데 중요한 파라미터가 된다. 운용 중 발생하는 높은 ARC는 시스템 성능 열화에 직접적인 원인이 된다. 본 논문에서는 APAR의 안정적인 운용을 위한 방안으로 ARC의 성능을 개선시키는 방안과 보호 회로를 통한 열화 방지 방안에 관하여 분석하였다. 실제 제작한 능동 위상 배열 안테나의 실험 결과를 통해 두 방안의 유효성을 검증하였다.

광 지연선로를 이용한 스퀸팅이 없는 위상배열 안테나의 근접장 서브파장 포커싱 (Squint-less Phased Array Antenna Near-field Subwavelength Focusing with True-time Optical Delay Line)

  • 정영진
    • 한국광학회지
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    • 제30권3호
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    • pp.94-100
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    • 2019
  • 본 연구에서는 광 지연선로를 이용한 스퀸팅(squinting)이 없는 위상배열 안테나의 근접장 미세파장 포커싱(subwavelength focusing)을 디자인하고 전산모사를 통해 검증하였다. 마이크로파 파장에서 위상배열 안테나의 수치적 계산을 위해 호이겐스-프레넬(Huygens-Fresnel) 원리를 적용하였다. 제안하는 시스템은 첩 광섬유 격자(chirped fiber grating)에 기반한 광 지연선로를 이용하여 빔 스퀸팅이 생기지 않는다는 것을 전산모사를 통해 확인하였다. 그리고 개별 안테나의 배열은 광학렌즈시스템에서 회절 소자로 간주할 수 있음에 착안해 높은 개구율(numerical aperture)을 구현하고 미세파장 포커싱을 얻었다. 또한, 위상배열 안테나의 안테나 사이 거리를 반파장 이하로 줄여 사이드 로브를 억제할 수 있음을 보였다.

LHTL 위상변위기를 이용한 4×4 광대역 위상배열안테나 (4×4 Broadband Phased Array Antenna Using LHTL Based Phase Shifter)

  • 박순우;김홍준
    • 전기학회논문지
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    • 제66권2호
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    • pp.379-382
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    • 2017
  • This paper proposes a $4{\times}4$ broadband phased array antenna using a Left-Handed Transmission Line (LHTL) based phase shifter. The phased array is constructed with sixteen quasi-Yagi antenna elements and the phase shifters, as well as four power dividers. A key component of the system, the LHTL based phase shifter is able to control a phase delay of incident waves linearly and continuously. The fabricated phased array antenna operate for a frequency range of 800 MHz (1.6 GHz~2.4 GHz). The beam scanning range of the $4{\times}4$ array antenna is ${\pm}27^{\circ}$ horizontally and vertically while the antenna gain is maintained with a variation of ${\pm}1.4dBi$.

바랙터다이오드에 의한 능동 위상차 배열 안테나의 발진 주파수 가변 범위의 확장 (Expansion of Variable Range of Oscillation Frequency of Active Phased Array Antenna by a Varactor Diode)

  • 최영규
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제52권11호
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    • pp.521-528
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    • 2003
  • A varactor diode was utilized in order to expand variable range of the natural oscillation frequency of an active phased-array antenna. We have conformed experimentally that the variable range of the natural oscillation frequency was expanded about three times in the oscillator controlled by the varactor diode. When frequency difference was given to the oscillators in the two elements antenna system, phase difference was appeared between the oscillators. The 2-, 3-, 5-elements patch antenna array was composed for the beam scanning experiments. All the above patch antennas showed good phased array characteristics. The experimental results are as follows that the scanning angle of the 2-elements array antenna is 28.6$^{\circ}$, the 3-elements array antenna is 29.4$^{\circ}$, and the 5-elements array antenna is 26.2$^{\circ}$.