Agency For Defense Development Research Articles

무기체계개발 사업에서 체계공학 프로세스 기반 사업성과관리 수행 방안

Agency for Defense DevelopmentAbstract : It is generally recommended to use EVM as an efficient means for measuring project performance and progress so that the EVMS user could manage his project suc cessfully. In spite of it’s favorable intention, most project participants think it as a heavy load o r a sub practiced job with low responsib ility. Even though there are lots of variables triggering unpredictabl e troubles in EVM application, EVM st ill could be a valuable project health indicator. In this paper we introd uce a performing method for EVM based on system engineering process.Key Words : EVM, Earned Value Management, System Engineering Process, We apon R&D Project* 교신저자 : Seung Hak Kuk, shkuk@add.re.kr* This is an Open-Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License(http://creativecommons.org/licenses/by-nc/3.0) which pe rmits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

육군 항공기류 UHF 대역 송수신기 CE101 시험

Abstract In case of UHF Band Transceiver for Army Aircraft, it shall follow MIL-STD-461F Figure CE101-4 most key design points for this equipment were to minize the current consumption and frequency interference since it will be integrated on aircraft. However, after design, abnomal signal(over 100 dBuA) was occured from 30 Hz to 1 kHz on CE101 test. Occured abnomal signal was measured as 50 Hz signal which was tansceiver T DD signal with the output power of 10 W and 20 ms periods. To meet the specification, current variation needed to be minized. Thus, I dq and I d of power amplifier were modified almost equally through test result and finally, the equipment was designed and developed with no difference of current consumption and frequency interference from the previous design goal.Key words: CE101, UHF Band, T DD , Army Aircraft U‚ƒ„(Department of Electronic Engineering Hanwa Thales) *<v †‡J(Agency for Defense Development) bManuscript received October 8, 2015 ; Revised November 11, 2015 ; Accepted November 19, 2015. (ID No. 20151008-073)bCorresponding Author: Jung-Won Seo (e-mail: jungwon81.seo@hanwha.com)

하이브리드 방법을 이용한 다층 미앤더선로 구조의 3:1 광대역 원편파 편파기 설계

Abstract In this paper, a wideband circular polarizer operating in the frequency range of 6<18 GHz is designed and fabricated using a multilayer structure with meanderlines. A T matrix expression for the unit structure, which consists of meanderline, dielectric substrate and spacer, was derived using the boundary value solution. A proposed meanderline structure was modeled as an array of unit meanderline cell in order to apply the waveguide model with PEC and PMC boundary conditions. The calculation procedures to obtain an equivalent susceptance of the unit meanderline cell using HFSS was also suggested. Using a hybrid method, which combines the T matrix with the HFSS results, and cut-and-try method, a wideband circular polarizer with low insertion loss and good AR performance was designed. The fabricated polarizer has the return loss less than 10 dB within 92 % bandwidth, the average insertion loss less than 0.24 dB, and the average AR below 2.6 dB for full 3:1 bandwidth. Key words: Wideband Circular Polarizer, Meanderline „in oCS(Agency for Defense Development) *†‡ ˆ ‰ n(Department of Radio Science & Engineering, Chung-Nam National University) 8Manuscript received July 31, 2015 ; Revised August 26, 2015 ; Accepted August 26, 2015. (ID No. 20150731-053)8Corresponding Author: Jeong-Ki Pack (e-mail: jkpack@cnu.ac.kr)

Exploration of Metal Oxide Catalysts for Direct Urine Fuel Cell and Gas Sensors for Its Condition Monitoring

The technology to use hydrogen as an attractive energy resource is in development. However, storage of hydrogen is still considered as a major drawback. An alternative approach has been investigated to use light chemicals as a hydrogen source such as methanol, ammonia or urea (1-4). Urea is a non-toxic and low-cost industrial product as well as naturally exists in urine and waste water. Urea / urine fuel cell can be applied to treatment of waste water, animal waste, waste supplier of manned spaceship, power of electrical vehicles and portable equipment (3). Since the mechanisms of chemical reaction on urine conversion are not well understood, an economic method to rapidly evaluate the chemical species inside the fuel cell can provide insights to understand the mechanisms. Among critical components to construct a fuel cell, catalyst can be an important material for urine/urea conversion. Nickel, an inexpensive transition metal, has been investigated as a catalyst for the urine / urea fuel cell. Boggs et al. (2) demonstrated the direct conversion of urine and urea to hydrogen using electrochemical oxidation with a nickel catalyst. Lan et al. (4) synthesized nanostructured nickel and applied it as an anode catalyst for fuel cells. Transition metal oxides also show catalytic processes due to their selectivity on oxidation, reduction and dehydrogenation (5). Electrochemical properties of nickel oxide has been studied to apply capacitors (6), electrochromic thin films (7), phenol degradation (8), and biosensors (9). Therefore, nickel oxide is considered as a potential catalyst of urea / urine oxidation. In this study, nanostructured nickel oxide is synthesized using a hydrothermal method and a precipitation method with different morphology. The crystal structure and morphology after calcination are shown in Fig. 1 and Fig. 2, respectively. Different ratios of mixtures with synthesized nickel oxide and graphene oxide are fabricated to films by electrophoretic deposition (EPD). Parameters in EPD were controlled to construct different hierarchical structures. The structural properties of the deposited nickel oxide layers are analyzed by using SEM and XRD. Then, the catalytic effects were also investigated. The use of gas sensors to measure cell reaction will be performed to advance fundamental understanding of direct conversion of urine. This research was partially supported by Agency for Defense Development (ADD) as global corporative research and Auburn University IGP. 1. Brown, L. F. (2001) International Journal of Hydrogen Energy 26, 381-397 2. Boggs, B. K., and Botte, G. G. (2009) Journal of Power Sources 192, 573-581 3. Lan, R., Tao, S., and Irvine, J. T. (2010) Energy & Environmental Science 3, 438-441 4. Lan, R., and Tao, S. (2011) Journal of Power Sources 196, 5021-5026 5. Kung, H. H. (1989) Transition metal oxides: surface chemistry and catalysis, Elsevier 6. Xing, W., Li, F., Yan, Z.-f., and Lu, G. (2004) Journal of Power Sources 134, 324-330 7. Kamal, H., Elmaghraby, E., Ali, S., and Abdel-Hady, K. (2005) Thin Solid Films 483, 330-339 8. Lai, T.-L., Lee, C.-C., Wu, K.-S., Shu, Y.-Y., and Wang, C.-B. (2006) Applied Catalysis B: Environmental 68, 147-153 9. Salimi, A., Sharifi, E., Noorbakhsh, A., and Soltanian, S. (2007) Biosensors and Bioelectronics 22, 3146-3153 Figure 1

Gas Sensing Properties of Hierarchically Structured Zinc Oxide Films By Electrophoretic Deposition

During last years, the interest in wearable devices has increased significantly. A portable and wearable gas sensor system is one area of interest. Integration of fabric and gas sensors for a wearable breath monitoring system would monitor signature gas from patients’ breath such as acetone gas for diabetes (1), ammonia for renal disease (2), and ethanol for hepatic steatosis (3). Breath sensing system is painless, faster and potentially less expensive than blood tests - and easy to repeat as often as needed, even while patients are sleeping or exercising. Semiconducting nano-scale metal oxides such as tin oxide (4), zinc oxide (5), and nickel oxide (6) have been used to develop gas sensors. Among them, zinc oxide, which shows n-type behavior, is one of excellent candidates because of its electric properties such as wide band gap and high electron mobility (5). Various morphologies for ZnO nanostructures such as nanorods, nanotubes, and nanowires have been investigated to understand morphology-driven properties. Recently, hollow micro/nanosphere ZnO has been fabricated and its properties have been investigated. Such structure may be applied for dye-sensitised solar cells, photocatalts, high performance electrodes, and gas sensors due to its large surface-to-volume ratio and reduced transport lengths for both mass and charge transport (7). In this study, the hollow microsphere ZnO particles were prepared by a simple precipitate method. The crystal structure and morphology after calcination are shown in Fig. 1 and Fig. 2, respectively. Electrophoretic deposition (EPD) was then used to construct ZnO layers on flexible substrates. The structural properties of the deposited ZnO layers were analyzed by using SEM, TEM, and XRD. Then, gas sensing behaviors to detect ethanol and acetone by morphological variation of layers are discussed in detail. This research was partially supported by Agency for Defense Development (ADD) as global corporative research and Auburn University IGP. 1. Zhang, Q., Wang, P., Li, J., and Gao, X. (2000) Biosensors and Bioelectronics 15, 249-256 2. Moorhead, K. T., Lee, D., Chase, J. G., Moot, A., Ledingham, K., Scotter, J., Allardyce, R., Senthilmohan, S., and Endre, Z. (2008) Computer methods and programs in biomedicine 89, 226-238 3. de Lacy Costello, B., Ewen, R., Ratcliffe, N. M., and Richards, M. (2008) Journal of Breath Research 2, 037017 4. Ahn, H., Noh, J. H., Kim, S.-B., Overfelt, R. A., Yoon, Y. S., and Kim, D.-J. (2010) Materials Chemistry and Physics 124, 563-568 5. Ahn, H., Park, J.-H., Kim, S.-B., Jee, S. H., Yoon, Y. S., and Kim, D.-J. (2010) Electrochemical and Solid-State Letters 13, J125-J128 6. Dirksen, J. A., Duval, K., and Ring, T. A. (2001) Sensors and Actuators B: Chemical 80, 106-115 7. Xie, Q., Li, J., Tian, Q., and Shi, R. (2012) Journal of Materials Chemistry 22, 13541-13547 Figure 1

생물안전 3등급 연구시설의 구성 및 이용

Laboratory facilities for biology are designed as biosafety level 1, biosafety level 2, biosafety level 3, and biosafety level 4. Biosafety level designations are based on a composite of the design features, construction, containment facilities, equipment, practice and operation procedures required for working with agents from the various risk groups. Generally, biosafety level 3 means the facility that is appropriate for the experiments using pathogens which can cause serious diseases by aerosol transmission. The biosafety level assigned for the specific work to be done is driven by professional judgement based on a risk assessment, rather than by automatic assignment according to the particular risk group designation of the pathogenic agents to be used. In this paper, we introduced the biosafety level 3 facility operated in ADD(Agency for defense development). It contains the overview of facility, microbiological experiment, animal experiment, decontamination and waste disposal. Biosafety level 3 laboratory in ADD has served the vital role in the research of biological agents and antidote development.

휴대용 유도탄의 후방 안전영역 평가방법에 관한 연구

Recoilless weapons, which lead strong back blast and impulse noise more than 160 dB, have been used in compliance with the regulation of the safety zone for the safe operations. However, the safety zone regulations for the newly developed weapons should be prepared since the existing guidelines do not provide any information concerning the reason for the safety zone. In this study, the outdoor launch tests were performed to collect the data such as noise, pressure and temperature of the back blast. An assessment method using data obtained from launch tests has been proposed to determine the safety zone. The safety zone has been determined with consideration for the following criteria: Impulse noise, temperature and pressure of the back blast and blast angle. As a results, new safety zones for them have been established for the recoilless weapon developed by ADD (Agency for Defense Development). We expect that this research can be used as a guideline for establishing a new safety zone regulation of similar weapon to be developed.

Gas Sensing Behaviors of Hierarchically Structured Nickel Oxide Film By Electrophoretic Deposition

Over the past few years, the interest in wearable devices has increased dramatically. A highly miniaturized and wearable gas sensor system is one of interests. Integration of fabric and gas sensors for a wearable breath monitoring system would allow continuous monitoring patients’ breathe gases such as acetone gas for diabetes [1], ammonia for renal disease [2], and ethanol for hepatic steatosis [3]. Thus, there has been demands to fabricate wearable gas sensing system operating at daily environment. Semiconducting nano-scale metal oxides such as tin oxide [4], zinc oxide [5], and nickel oxide [6] have been developed to apply gas sensors. Among them, nickel oxide, which shows p-type behavior, has outstanding electrical and optical properties as well as chemical stability. There have been different approaches to synthesize nickel oxide films, such as physical and chemical vapor deposition. In this study, the particles with different morphology were first prepared by solution based synthesis method by using different precursors. Electrophoretic deposition (EPD) was then used to construct hierarchically structured NiO films. The nickel oxide was prepared by precipitation followed by calcination of nickel hydroxide-based precursors prepared by nickel acetate, nickel chloride or nickel nitrate. Morphology-tunable NiO nanoparticles were designed and prepared by heat treating different forms of nickel hydroxide precursors. By intercalating different size of anions (Cl- < NO3 - < CH3COO-) [7], different size and morphologies of precipitates are expected. The crystal structure and morphology by calcination are shown in Fig. 1 and Fig. 2, respectively. Each nickel oxide nanoparticles were coated to films by EPD process. Parameters in EPD were controlled to construct different hierarchical structures. The structural properties of the deposited nickel oxide layers are analyzed by using SEM and XRD. Then, gas sensing behaviors to detect ethanol by morphological variation of layers are discussed in detail. This research was partially supported by Agency for Defense Development (ADD) as global corporative research for direct urine fuel cell and Auburn University IGP. Figure Caption Fig. 1 XRD patterns of synthesized (a) as-precipitated Ni(OH)2 and (b) calcined NiO at 300 °C for 1 hr and 3 hr. Fig. 2. Morphology of (a) the as-precipitated nickel hydroxide particles and calcined NiO particles at 300 °C for (b) 1 hr and (c) 3 hr. Refernce 1. Zhang, Q., P. Wang, J. Li, and X. Gao, Biosens. Bioelectron., 15[5](2000)249-256. 2. Moorhead, K.T., D. Lee, J.G. Chase, A. Moot, K. Ledingham, J. Scotter, R. Allardyce, S. Senthilmohan, and Z. Endre, Computer methods and programs in biomedicine, 89[3](2008)226-238. 3. de Lacy Costello, B., R. Ewen, N.M. Ratcliffe, and M. Richards, J. Breath Res., 2[3](2008)037017. 4. Ahn, H., J.H. Noh, S.-B. Kim, R.A. Overfelt, Y.S. Yoon, and D.-J. Kim, Mater. Chem. Phys., 124[1](2010)563-568. 5. Ahn, H., J.-H. Park, S.-B. Kim, S.H. Jee, Y.S. Yoon, and D.-J. Kim, Electrochem. Solid-State Lett., 13[11](2010)J125-J128. 6. Dirksen, J.A., K. Duval, and T.A. Ring, Sensors and Actuators B: Chemical, 80[2](2001)106-115. 7. Meher, S.K., P. Justin, and G.R. Rao, Nanoscale, 3[2](2011)683-692. Figure 1

DEVS 통합개발환경 기반 모의 어뢰 표적탐지부 연동장비 개발

ABSTRACTIt is necessary for us to undergo trial and error for eliciting the rational requirement of the acquisition of weapon systems, but the M&S is general approach due to costs and risk of the development. In addition to the acquisition of weapon systems, M&S is extensively employed in the analysis and the training of developed weapon systems. The ADD (Agency for Defense Development) has developed DEVS integrated development environment (QUEST) that provides M&S general ground technique composed of simulation model implementation services, simulation result analysis services, and simulation interface services. This paper describes the interface architecture and the implementation of torpedo target detection section interface simulation system using QUEST. The torpedo target detection section interface simulation system is composed of torpedo target detection section which calculates a result of target detection and the QUEST scenario generator which provides simulation scenario for performance test of the torpedo target detection section. The interface architecture of torpedo target detection section interface simulation system is designed to verify the interface and performance of the torpedo target detection section by linking with the QUEST scenario generator.

무인항공기의 노즐 형상 변화가 Lock-on Range에 미치는 영향에 관한 연구

韓國航空宇宙學會誌 , ** , *** Agency for Defense Development**** ABSTRACT The infrared lock-on range of target aircraft plays a critical role in determining the aircraft survivability. In this investigation, the effects of various UAV engine nozzle configurations on the aircraft lock-on range were theoretically analyzed. A virtual subsonic aircraft was proposed first, based on the mission requirement a nd the engine performance analysis, and convergent-type nozzles were then designed. After determining thermal flow field and nozzle surface temperature distribution with the CFD code, an additional analysis was conducted to predict the IR signature. Also, atmospheric transmissivity for various latitude and seasons was calculated, using the LOWTRAN code. Finally, the lock-on and lethal envelopes were calculated for different nozzle configurations, assuming the sensor threshold of the given IR guided missile. It was shown that the maximum 55.3% reduction in lock-on range is possible for deformed nozzles with the high aspect ratio.

람다 날개 형상의 옆미끄럼각 효과에 대한 실험적 연구

ABSTRACT An experimental study on aerodynamic coefficients of a lambda w ing configuration was performed at the low speed wind tunnel of Agency for Defense Development. The main purpose of this study was to investigate the effects of sidesli p angle on various aerodynamic coefficients. In the case of 0 ° sideslip angle, nose-up pitching moment rapidly increases at a specific angle of attack. This unstable pitching moment characteristic is referred to as pitch break or pitch up. As the sideslip angle increases, the pitch break is found to be generated at a higher angle of attack. Rolling mome nt is found to show similar behavior pattern to ‘pitch break’ style with angle of attack at non-zero sideslip angles. This trend gets severer at greater sideslip angles. Yawing moment also shows substantial variation of the slope and the unstable directional stability with sideslip angles at higher angles of attack. These characteristics of the three moments clearly implies the difficulty of the flight control which requires efficient contr ol augmentation system.

고속 주파수 합성기용 광대역 DDS 모듈

Abstract In this paper, a wideband DDS module covering the frequency range from 0.5 to 1.1 GHz was designed and fabricated. The clock frequency of the DDS was selected 2.4 GHz in order for 600 MHz output bandwidth. Multiple spurious cancelling signals having same amplitude and 180 ° phase difference compared to the spurious were created at the additional path and added to the output signal within DDS for the spurious performance improvement. The fabricated DDS module showed better spurious performance than the commercial DDS one more than 10 dB and frequency tuning time was 340 ns below.Key words: Wideband Synthesizer, DDS, Spurious Cancellation UV WX'Y(Agency for Defense Development) *Z[W\]^W (Department of Radio Science & Engineering, Chungnam National University) Manuscript received August 29, 2014 ; Revised September 29, 2014 ; Accepted November 7, 2014. (ID No. 20140829-065)Corresponding Author: Dong-Chul Park (e-mail: dcpark@cnu.ac.kr) _. 서 론 6(A`Qabc,12de f ]ghiK 1jk <L:l m, nb 6712!Po+BCAp q I4 r0+#$. st! 1jknbuA%(instantaneous bandwidth)o+T $v#12w 12:@AxyMz+nbuA@{ :|f m, Q+T /01234Q} l # I4 :0'J$. ~!PDAC(Digital-to-Analog Converter)QK# €I4 B‚+DDSQK#!P/-ƒ I4Q:„ e , 12†e‡I4o+T#3x/012ˆ‰ ŠJ$

ML 기법을 이용한 PCM 파형에서의 표적 탐지 및 도플러 추정

Abstract Characteristics of PCM(Pulse Code Modulation) waveform are suitable for target tracking. Especially in terms of dwell time, it is desirable to detect and track a moving target with the single PCM waveform for a MFR(Multi-Function Radar) which carries out multiple tasks. General PCM waveform processing includes Doppler filter bank caused by the characteristics of ambiguity function, to detect target and estimate Doppler frequency, which induces hardware burden and computational complexity. We propose a ML(Maximum Likelihood) based Doppler estimator for a PCM waveform, which is the closed form suboptimal solution and computationally efficient to estimate Doppler frequency and detect a moving target. Key words: Pulse Code Modulation Waveform, Doppler Frequency Estimation, Multi-Function Radar, Target Detection h\Tijkl(Agency for Defense Development)Manuscript received August 26, 2014 ; Revised October 15, 2014 ; Accepted November 4, 2014. (ID No. 20140826-063)Corresponding Author: Eunjung Yang (e-mail: ejyang@add.re.kr)

DDS를 이용한 광대역 고속 주파수 합성기

Abstract In this paper, a 613 GHz ultra high speed frequency synthesizer having minimum 30 kHz step size and minimum 500 ns frequency settling time is proposed. In order to obtain fast settling time, fine resolution, and good phase noise performance, wideband output frequencies were synthesized based on DDS(Direct Digital Synthesizer) and analog direct frequency synthesis technology. The phase noise performance of wideband frequency synthesizer was estimated by the superposition theory and its results were compared with mea-sured ones. The measured frequency settling time was below 500 ns, phase noise was below 106 dBc @ 10 kHz at 13 GHz, and frequency accuracy was measured below ±2 kHz. Key words: Wideband Synthesizer, High Speed, Fine Resolution, DDS OPQRS(Agency for Defense Development) *TU QGVWQ(Department of Radio Science & Engineering, Chungnam National University)Manuscript received August 29, 2014 ; Revised September 29, 2014 ; Accepted November 7, 2014. (ID No. 20140829-066)Corresponding Author: Dong-Chul Park (e-mail: dcpark@cnu.ac.kr)

Adaptive passive fathometer processing of surface-generated noise received by Nested array

Recently, a passive fathometer technique using surface-generated ambient noise has been applied to the estimate of bottom profile. This technique performs the beamforming of ambient noise received by a vertical line array to estimate the sub-bottom layer structure as well as water depth. In the previous works, the surface noise signal processing was performed with equally spaced line arrays and the main topic of the research was the comparison of the results estimated using several beamforming techniques. In this talk, the results estimated from the ambient noise received by the Nested vertical line array (called POEMS) which consists of the total 24-elments and four sub-bands are presented. The measurements were made on the eastern coast (East Sea) of Korea. Four kinds of beamforming algorithms are applied to each sub-band and also, nested array processing combining each sub-band signal was performed to obtain the best result. The results are compared to the bottom profiles from the chirp sonar. [This research was supported by the Agency for Defense Development, Korea.]

이중 PLL 구조 주파수 합성기의 위상 잡음 개선

Abstract This paper proposes a high speed frequency synthesizer with dual phase-locked loop(PLL) structure to improve phase noise level and shape in a wideband receiver. To reduce phase noise and fractional spur, a output frequency of 1 st PLL used as reference frequency of 2 nd PLL is changed. The frequency synthesizer has been designed with 1 Hz frequency resolution using digital NCO in 6.5A8.5 GHz wide spectrum. The measured results of the fabricated frequency synthesizer show that the output power is about 3 dBm, the maximum lock-in time and phase noise are within 60 us and 95 dBc/Hz at 10 kHz offset, respectively.Key words: Frequency Synthesizer, Dual PLL, Phase Noise, Fractional Spur QRSTE%U(Agency for Defense Development)Manuscript received July 21, 2014 ; Revised September 5, 2014 ; Accepted September 12, 2014. (ID No. 20140721-11S)Corresponding Author: Jung-Hoon Kim(e-mail: jhkim1@add.re.kr) V. 서 론 WXY!Z [O ], Y!^_`, abcdefg9hi j 3klm, 9no#_ Npq mHr s*2tudvwN3klm-. Y!Z udv'( )* LO(Local Oscillator) 1wx23y0z{|}#-. '( )*)*R~€‚ #9ƒ„'( )*(DS: Direct Synthe-sis), „)*R~(PLL), ƒ„BCD)*R~(DDS: Direct Digital Synthesis) eG†‡ˆlm

국방 자기분야 연구를 위한 국방과학연구소 시험시설

국방과학연구소는 수중 자기 스텔스 분야의 핵심기술 개발, 자기응용 무기체계 연구 및 국방 자기분야의 대군 기술지원 업무 수행을 위해 1990년대 이후로 비자성 실험실과 자기센서 실험실을 운용 중에 있다. 최근 실험실내 주요 시험 장비의 성능을 개량하여 자기 표적에 대한 정밀 측정 및 분석 능력을 향상시켰으며, 무기체계에 적용하기 위한 자기센서들에 대한 정밀 시험 평가 능력을 확보하였다. 본 논문에서는 국방과학연구소 자기 시험 시설의 현황 및 시험 능력에 대해 상세히 기술하고자 한다. Since 1990, Agency for Defense Development (ADD) has been operating the nonmagnetic laboratory and the magnetic sensors laboratory to develop the key technology of the ship's magnetic silencing and to research the high performance magnetic sensors used in the weapon system and to perform the technical support for Republic of Korea Navy. Recently, the main test equipment in the laboratories has been upgraded to improve the measurement and analysis abilities against magnetic target and to evaluate the performance of the magnetic sensors. In this paper, the capability and the current state of magnetic test facilities of ADD are described.

2차원 Matrix Pencil Method 기반의 바이스태틱 MIMO 레이더 표적 도래각 추정

Abstract In this paper, we apply the 2-D Matrix Pencil Method(MPM) to the estimation of the direction of arrival(DOA) of multiple signals of interest(SOIs) in bistatic MIMO radar. The 2-D MPM shows remarkable performance under a low SNR environment and low computational complexity to estimate the DOA of multiple SOIs. Also, it is possible to estimate the direction of departure(DOD) which is an angle from transmitter to target. To verify the proposed algorithm, we applied the proposed algorithm to a uniformly spaced linear array(ULA) and compared the RMSE(Root Mean Square Error) of DOA and DOD under the various SNR with those of the 2-D Capon algorithm.Key words: MIMO Radar, DOA/DOD, 2-D Matrix Pencil Method O0FPQRSMTPMU0FV6W %TPXYWZV [\]0F^_QRM2012`+abcUNNdU[0F-e)345fghij.k abcUNlmnopUM(Department of Electronic Convergence Engineering, Kwangwoon University) * qcUNrs_tpUu(Division of Computer and Communications Engineering, Korea University)**TPMU0FV(Agency for Defense Development)Manuscript received May 8, 2014 ; Revised May 30, 2014 ; Accepted June 2, 2014. (ID No. 20140508-043)Corresponding Author: Young-Seek Chung (e-mail: yschung@kw.ac.kr)

재밍대응 5소자 평면 GPS 배열 안테나 설계

Abstract This paper describes the design and analysis of five-element planar array antenna of an anti-jamming satellite navigation system. We propose a design of multi-layer patch antenna for Global Positioning System(GPS) L 1 /L 2 dual bands. The proposed antenna has two ports feeding network with a hybrid chip coupler for a broad bandwidth with Right-Handed Circular Polarization(RHCP). The measurement results show the bore-sight gains of 1.10 dBic(L 1 ) and 0.37 dBic(L 2 ) for the center element. The bore-sight gains of an edge element are 0.99 dBic(L 1 ) and 0.57 dBic(L 2 ). At a fixed elevation angle of 30°, antennas show average gains of 2.08 dBic (L 1 ) and 5.33 dBic(L 2 ) for the center element, and average gains of 0.40 dBic(L 1 ) and 2.09 dBic(L 2 ) for the edge elements. The results demonstrate that the proposed array antenna is suitable for anti-jamming applications.Key words: Anti-Jamming, CRPA(Controlled Reception Pattern Antenna), Patch Antenna, Feeding Structure, Circular Polarization, Array Antenna RGEST)(Agency for Defense Development)UManuscript received February 10, 2014 ; Revised April 3, 2014 ; Accepted April 4, 2014. (ID No. 20140210-024)UCorresponding Author: Seung Mo Seo (e-mail: sms@add.re.kr)

절연재에 따른 TEM 안테나의 방사패턴 및 이득 변화

Abstract - TEM Horn antenna is typically used in HPEM area. It is necessary to apply a high voltage of the antenna for radiating HPEM. Then, it is necessary to insulate essentially of applying a high voltage to the antenna. At this time, radiation pattern and gain of the TEM Antenna is changed. For this reason, it is necessary to analyze changing characteristics by using simulation. In this paper, I analyzed the radiation pattern of the antenna in accordance with the lens and insulating material. As a result, it was observed that the value of the gain is changed in accordance with the frequency. The lens is used for the antenna, the gain characteristic is improved.Key Words : TEM horn antenna, TEM antenna insulation, Far-field pattern † Corresponding Author : Dept. of Electrical Engineering, INHA University, KoreaE-mail : cshuh@inha.ac.kr* Dept. of Electrical Engineering, INHA University, Korea** Agency for Defense Development***Korea Testing & Research Institute, (KTR)Received : December 10, 2013; Accepted : March 31, 2014