• Title/Summary/Keyword: Active Phase Array

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A Design and Fabrication of a Compact Ka Band Transmit/Receive Module Using a Quad-Pack (쿼드팩을 이용한 소형 Ka 대역 송수신(T/R) 모듈의 설계 및 제작)

  • Oh, Hyun-Seok;Yeom, Kyung-Whan;Chong, Min-Kil;Na, Hyung-Gi;Lee, Sang-Joo;Lee, Ki-Won;Nam, Byung-Chang
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.3
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    • pp.389-398
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    • 2011
  • In this paper, the design and fabrication of a transmit/receive(T/R) module for Ka-band phased array radar is presented. A 5bit digital phase shifter and digital attenuator were used in common for both transmitter and receiver considering unique Ka-band characteristic. The circulator was excluded in the T/R module and was placed outside T/R module. The transmitting power per element antenna is designed to be about 1 W and the noise figure is designed to be below 8 dB. The designed T/R module RF part has a compact size of $5\;mm{\times}4\;mm{\times}57\;mm$. In order to implement the T/R module, MMICs used in T/R module was separately assessed before assembly of the designed T/R module. The transmitter of the fabricated T/R module shows about 1 W at 5 dBm unit module input power and the receiver shows a gain of about 20 dB and a noise figure of below 8 dB as expected in the design stage.

Design of Ground Clutter Prevention Fences for Radar Wind Profiler (연직바람 관측장비를 위한 지형 클러터 방지 펜스 설계)

  • WooJae Jung;JongChul Lee;JungIk Jeon;HyeongKi Lee
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.21 no.6
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    • pp.241-249
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    • 2022
  • This paper discusses the design of a ground clutter prevention fence for a radar wind profiler (RWP). The design point of the clutter fence is to improve the quality of the received signal by removing the non-weather clutter coming from the side. In this paper, a clutter prevention fence composed of a metallash mesh around the RWP is proposed, and the phase center of the antenna, the length, and height of the down fence, and the height and slop of the top fence through M&S are designed. The designed ground clutter prevention fence and 256 active phase array antennas were used as basic data. The effectiveness of the design was confirmed by a simulation. The side lobe in the ±90° direction was reduced by more than 30dB depending on the presence or absence of the designed ground clutter prevention fence. The fence was manufactured by 3D modeling, and the clutter shielding performance of approximately 20dB or more on the side of the antenna (±90°) was confirmed by applying it to the currently operated RWP.

Development and Performance Compensation of the Extremely Stable Transceiver System for High Resolution Wideband Active Phased Array Synthetic Aperture Radar (고해상도 능동 위상 배열 영상 레이더를 위한 고안정 송수신 시스템 개발 및 성능 보정 연구)

  • Sung, Jin-Bong;Kim, Se-Young;Lee, Jong-Hwan;Jeon, Byeong-Tae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.6
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    • pp.573-582
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    • 2010
  • In this paper, X-band transceiver for high resolution wideband SAR systems is designed and fabricated. Also as a technique for enhancing the performance, error compensation algorithm is presented. The transceiver for SAR system is composed of transmitter, receiver, switch matrix and frequency generator. The receiver especially has 2 channel mono-pulse structure for ground moving target indication. The transceiver is able to provide the deramping signal for high resolution mode and select the receive bandwidth for receiving according to the operation mode. The transceiver had over 300 MHz bandwidth in X-band and 13.3 dBm output power which is appropriate to drive the T/R module. The receiver gain and noise figure was 39 dB and 3.96 dB respectively. The receive dynamic range was 30 dB and amplitude imbalance and phase imbalance of I/Q channel was ${\pm}$0.38 dBm and ${\pm}$3.47 degree respectively. The transceiver meets the required electrical performances through the individual tests. This paper shows the pulse error term depending on SAR performance was analyzed and range IRF was enhanced by applying the compensation technique.

SOURCE-FREQUENCY PHASE-REFERENCING OBSERVATION OF AGNS WITH KAVA USING SIMULTANEOUS DUAL-FREQUENCY RECEIVING

  • Zhao, Guang-Yao;Jung, Taehyun;Sohn, Bong Won;Kino, Motoki;Honma, Mareki;Dodson, Richard;Rioja, Maria;Han, Seog-Tae;Shibata, Katsunori;Byun, Do-Young;Akiyama, Kazunori;Algaba, Juan-Carlos;An, Tao;Cheng, Xiaopeng;Cho, Ilje;Cui, Yuzhu;Hada, Kazuhiro;Hodgson, Jeffrey A.;Jiang, Wu;Lee, Jee Won;Lee, Jeong Ae;Niinuma, Kotaro;Park, Jong-Ho;Ro, Hyunwook;Sawada-Satoh, Satoko;Shen, Zhi-Qiang;Tazaki, Fumie;Trippe, Sascha;Wajima, Kiyoaki;Zhang, Yingkang
    • Journal of The Korean Astronomical Society
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    • v.52 no.1
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    • pp.23-30
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    • 2019
  • The KVN(Korean VLBI Network)-style simultaneous multi-frequency receiving mode is demonstrated to be promising for mm-VLBI observations. Recently, other Very long baseline interferometry (VLBI) facilities all over the globe start to implement compatible optics systems. Simultaneous dual/multi-frequency VLBI observations at mm wavelengths with international baselines are thus possible. In this paper, we present the results from the first successful simultaneous 22/43 GHz dual-frequency observation with KaVA(KVN and VERA array), including images and astrometric results. Our analysis shows that the newly implemented simultaneous receiving system has brought a significant extension of the coherence time of the 43 GHz visibility phases along the international baselines. The astrometric results obtained with KaVA are consistent with those obtained with the independent analysis of the KVN data. Our results thus confirm the good performance of the simultaneous receiving systems for the nonKVN stations. Future simultaneous observations with more global stations bring even higher sensitivity and micro-arcsecond level astrometric measurements of the targets.