• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4773-4779
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• 2012

In this paper we propose two types of reconfigurable 3-D beam steering antenna for intelligent or smart antenna system. Proposed antennas are composed of triangular(structure1.) or circuler(structure2.) loop structure and bended dipole antenna structure. This antenna can steer beam pattern of 6 direction at xy-plane state (0, 1, 2) and xz-plane state (3, 4, 5) by 4 switch motion with one antenna element. Antenna structure1. is symmetric equilibrium structures based on feeding point. There is no grounding point. As a result, designed antenna's gain is similar to dipole antenna. Also, As unbalanced structure by using CPWG in the form of a semicircular, structure2. is enhanced directivity. The operation frequency of antenna are 2.5 GHz(Structure1.) and 2.55 GHz(Structure2.), maximum gain is 1.04 ~ 2.06 dBi(Structure1. : Omni-directional beam), 1.6 ~ 4 dBi(structure2. : Directional beam). The overall HPBW is about over $160^{\circ}$ in the both of the xy-plane and xz-plane at structure1. and over $125^{\circ}$ at structure2.

• Journal of IKEEE
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• v.24 no.2
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• pp.626-631
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• 2020

In this paper, a study on beam synthesis technique of conformal array was performed. It is applied to various radar systems that can perform beam steering without deterioration of performance due to beam steering in a general linear arrangement. Unlike the beam synthesis technique in the planar linear array, the conformal array has a radiation element located on a curved surface, so it is necessary to compensate for a difference in length from the radaation element to the wave front surface. In addition, by calculating the offset angle for each radiation element and applying it during actual synthesis, it was possible to predict an accurate beam pattern. In this paper, length compensation and offset angle were calculated and applied to beam pattern synthesis to perform beam pattern comparison, and performance was compared through mathematical analysis.

• 한국정보통신설비학회:학술대회논문집
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• 2003.08a
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• pp.12-15
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• 2003

이동체 탑재형 안테나는 특성상 소형화 및 신호 추적 시간 단축이 중요한 요소이다. 이러한 특성은 위상변위기를 이용한 전자적인 빔 조향 방식으로 한층 더 보완할 수 있다. 현재 이동체에서 주로 사용되고 있는 DBS (Direct Broadcasting Satellite) 수신용 안테나는 패치 및 슬롯 형태의 안테나 소자를 배열하여 사용한다. 하지만 이러한 안테나 소자는 전방위각에 대해 인공위성 방향(앙각 45도)에서 이득 손실이 있기 때문에 위상변위기를 이용한 빔 조향 방식에서 사용하기에는 문제점을 가지고 있다. 따라서 모든 방위각에 대해 앙각 45도에서 최대 이득 특성을 갖는 안테나 소자를 이용해 이득 손실을 줄이는 것은 큰 의미가 있다. 본 논문에서는 monopole 주변에 PBG(Photonic Band Gap) 구조를 구현함으로써 표면파를 억제하여 앙각 45도 방향에서 최대 이득 특성을 보이는 안테나 소자를 제안한다.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2003.11a
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• pp.541-545
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• 2003

본 논문에서는 하나의 급전소자와 두개의 무급전 소자로 구성된 전 후방 지향성을 가진 비행체 탑재 능동 빔 조향 프린트형 야기-우다 안테나를 설계, 제작하였다. 제작된 안테나는 두개의 무급전 소자에 부착된 칩다이오드의 간단한 스위칭 작용(Open, Short)으로 지향성 다이버시티를 구현하였다. 그리고 모노폴 급전 소자와 두개의 무급전 소자와의 거리를 변화시켜 상호 임피던스의 영향이 고려된 최대 전.후방비를 찾았다. 중심주파수 1.81 GHz에서 모노폴 급전소자와 무급전소자간의 간격이 $0.25{\lambda}$일 때, 26.6 dB의 최대 전.후방비(Open-Short 또는 Short-Open)특성이 나타내었다. 이를 통해 후방에 있는 지상 통제소와 미사일의 비행 방향에 관계없이 교신 가능한 수신 레벨을 유지 할 수 있음을 확인하였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.12
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• pp.1340-1350
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• 2009

The design and implementation of planar Active Phased Array Antenna System are described in this paper. This Antenna system operates at X-band with its bandwidth 10 % and dual polarization is realized using dual slot feeding microstrip patch antenna and SPDT(Single Pole Double Through) switch. Array Structure is $16\times16$ triangular lattice structure and each array is composed of TR(Transmit & Receive) module with more than 40 dBm power. Each TR module includes digital attenuator and phase shifter so that antenna beam can be electronically steered over a scan angle$({\pm}60^{\circ})$. Measurement of antenna pattern is conducted using a near field chamber and the results coincide with the expected beam pattern. From these results, it can be convinced that this antenna can be used with control of beam steering and beam shaping.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.2
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• pp.111-118
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• 2016

This paper presents an X-band (9.375 GHz) $1{\times}2$ array microstrip antenna which is capable of active beam compensation for installation of an unmanned aerial vehicle (UAV). First of all, a basic $1{\times}2$ array microstrip antenna incorporated with wilkinson power divider was designed and performance of the array antenna was verified. Next, to verify beam steering performance of the designed array microstrip antenna, we fabricated a phase shifter, and the wilkinson power divider as module structure and measured characteristics of beam steering according to phase shifting. The main lobe is 0.6 dBi at $0^{\circ}$, and the side lobe decreased 18.8 dB. The reliable radiation pattern was achieved. Finally, an active beam steering microstrip array antenna attached with the phase shifter and the power divider on the back side of the antenna was designed and fabricated to install wing of UAV for compactness. The maximum gain is 0.1 dBi. Therefore, we obtained a basic antenna technology for compensating beam error according to wing deformation of an UAV installed array antennas.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.2
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• pp.168-173
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• 2008

In this paper, we have designed transmit/receive Module for X band which can be applied to active phase array radar system. AESA(active electrically beam steered array) is able to transmit high power as like TWTA with composition of TH Module and steer a main beam faster than mechanically steering system. The proposed structure of T/R Module for X band is brick type for physical structure, common leg structure electrically and small size design as MCM(multi chip module). The results show that the characteristic of proposed T/R module can fully cover the specification of required military radar application.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.12
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• pp.1190-1197
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• 2013

AESA(Active Electronically Scanned Array radar) radar is able to instantaneously and adaptively position and control the beam, and such adaptive beam pointing of AESA radar enables to remarkably improve the multi-mission capability. For this reason, radar resource management(RRM) becomes new challenging issue. RRM is a technique efficiently allocating finite resources, such as energy and time to each task in an optimal and intelligent way. This paper deals with a design of radar resource management algorithms and simulator implemented main algorithms for development of airborne AESA radar. In addition, evaluation results show that developed radar system satisfies a main requirement about simultaneous multiple target tracking and detection by adopting proposed algorithms.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.27 no.4
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• pp.358-368
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• 2016

In this paper, for the mechanical beam steering of the Cassegrain antenna, the steering performances of the main reflector tilting method are characterized, and the Cassegrain antenna for the antenna rotating method is designed and its performances are measured. In the Cassegrain antenna operating at W-band, the changes of characteristics due to changes in the sizes of the main/sub-reflectors and other structural changes are analyzed to obtain the structural variables satisfying the performance goal. The manufactured antenna in W-band shows the measured gain of 42.08 dBi, 3 dB beamwidth of $1.32^{\circ}$, $1.14^{\circ}$ and the return loss($S_{11}$) of -23.58 dB at the center frequency of 94 GHz.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.4
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• pp.63-73
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• 2021

The radar operated to detect/track aircraft targets is divided into a search radar that operates while the antenna rotating device rotates for the purpose of detecting the target according to the mission characteristics, and a tracking radar that periodically steers and tracks a beam to the predicted position of the target. The tracking radar has a shorter target information acquisition preiod than the search radar. Due to this characteristic, the tracking accuracy is better than that of the search radar, but as the prediction error increases due to the speed error at the beginning of the tracking, there are many cases in which tracking fails at the beginning of tracking due to failure to perform beam steering normally. In this paper, in order to solve the above-mentioned problems, we propose an algorithm for improving the accuracy of track initiation using radial velocity measurements in addition to the position of the measured, and confirm the performance of the proposed algorithm by comparing with the two point differential algorithm