• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.12A
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• pp.1168-1173
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• 2005

The HVPS of the TWTA for military satellite communications is developed and tested. With 380 V input DC voltage, the HVPS provides -10.95 kV for Cathode, -4.27 kV for Collectorl and -6.57 kV for Collector2 of the TWT that generates 600 W X-band output signal power. The total output power of the HVPS is about 1.6 kW. The voltage ripples of Cathode, Collectorl and Collector2 are 6 V, 12 V and 6 V, respectively, which are only $0.055\%,\;0.281\%$ and $0.091\%$ compared to the absolute output voltages.

• Journal of the Korea Institute of Military Science and Technology
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• v.21 no.6
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• pp.826-841
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• 2018

The military satellite communication of ROK military, ANASIS is designed for analog data such as voice and streaming data. ANASIS cannot fully support ALL-IP communications due to its long propagation delay. The next generation satellite communication system is being designed to overcome the limitation. Next generation satellite communications system considers both high-speed and low-speed networks to support various operating environment. The low-speed satellite supports both broadband and narrow-band communication. This network works as the infrastructure for of wide-area internetworking over multiple AS's in the terrestrial network. It requires minimum satellite frequency and minimum power and works without PEP and router. In this paper, we propose a network operation structure to enable the inter-operation between high and low-speed satellite networks. In addition, we propose a data link protocol for low speed satellite networks.

• Information and Communications Magazine
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• v.32 no.10
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• pp.18-23
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• 2015

위성 통신 기술의 비약적인 발전에 따라 군용 통신위성도 정보를 중계해주는 단순한 역할로부터 네트워크 중심전을 지향하는 군전술통신망의 중추적인 역할을 담당하게 될 것이다. 이에 따라 군 통신위성은 고속대용량 전송, 접속성, 생존성, 보안성 등 전술통신의 다양한 기능이 요구되며, 이러한 기능을 효율적으로 수행하기 위한 핵심요소가 디지털화된 OBP (On-Board Processing) 기술이다. 본고에서는 위성탑재 OBP의 환경 및 이에 따른 요구조건과 군위성에 탑재되는 OBP의 주요 기능인 채널화 및 역채널화, 항재밍 기술, 자원할당 기술 등에 대해 소개한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.8C
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• pp.637-644
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• 2012

In this paper, a new compact power divider is suggested. Instead of the quarter wavelength transmission line(TX-line)s for the branches of the conventional Wilkinson's power divider design method, we use our composite right- and left-handed(CRLH) TX-line zeroth order resonator(ZOR) bandpass filters of one twelfth wavelength and reduce the physical length of the power divider. Besides, the filters in the branches can secure the passband for power-division. To validate the proposed power divider, we take an L-band for millitary satellaite transponder as the test case and the performances of the circuit and full-wave simulation results with the CRLH properties of the structure are shown with the dispersion curve and E-field at the ZOR. The measurement is compared with the simulation results. Also, the size reduction effect by the proposed scheme is addressed

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.11B
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• pp.1696-1703
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• 2010

Increased demand for military satellite communications system and due to the depletion of resources of existing satellite communications frequencies, Ka-band and EHF-band satellite communication systems is growing demand for development. As a result, the study of rain attenuation mitigation for Ka/EHF-band frequencies has been achieved. The method to compensate rain attenuation on Ka-band(20/30) using the signal power measurement function in Digital Transponder of Next Military Satellite has been proposed in this paper. This method is more effective than generally used method by Beacon and UPC(uplink power control) in giving the precise rain attenuation measurement and correction.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.4
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• pp.393-400
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• 2014

In this paper, we have designed the transmitter for earth station terminal operating with military geostationary satellite on Ka-band that is complied with MIL-STD-188-164A. The designed antenna of this terminal is dual-offset gregorian reflector which is consist of corrugated horn and iris polarizer, othermode transducer. This antenna meets radiation pattern and transmit EIRP spectral density requirements in this standard. The designed RF systems of this terminal are consist of Block Up Converter(BUC) converting frequency band from IF to Ka band and SSPA having low-power consumption and compact light-weight using the pHEMT MMIC compound devices. This RF systems applied with VSWR, spurious/harmonic suppression, output flatness and phase noise requirement in this standard.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.1
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• pp.63-71
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• 2017

During the sea trial test, we discovered EMI(Electromagnetic Interference) between MIL-SATCOM parabolic antenna and ES(Electronic Warfare Support) omni antenna. Emitted side lobe of CW(Continuous Wave) from MIL-SATCOM raises the threshold level of ES omni antenna. Therefore detection rate of ES is decreased. To solve this problem, the path of side lobe of CW from MIL-SATCOM should be blocked using EMI shield. This paper presents the method how to calculate the size of EMI shield, material, and optimized deployment. The test of the EMI shield effect was performed on a surface ship. After installing EMI shield, EMI has been decreased significantly. This paper will provide a method how to design EMI shield and a way to verify the result.