• The Journal of the Korea institute of electronic communication sciences
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• v.9 no.4
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• pp.455-468
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• 2014

This paper presents seamless hand off implementation suggesting algorithm and Measuring /testing at the tunnel environment in order to derive the ideal value of wireless data transmission in RF-CBTC train control system modeled by Shinbundang Operation System. In addition, it proposes the ideal value(-57dB) for reducing the re-transmission or frequency interference rate and demonstrates frequency optimization which enables highly reliable data communication in Train control system using wireless communications. Based on these result, Shinbundang phase 2 plan to apply to this system.

• Information and Communications Magazine
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• v.21 no.6
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• pp.143-152
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• 2004

최근 RFID 국제 표준안이 확정되고 RFID 태그용 칩이 저가 생산이 가능하게 되면서 특히 물류 유통 분야를 중심으로 기존의 바코드를 대체하는 RFID 시스템의 상용화 가능성이 제시되고있다. 특히 감지거리가 길고 인식률이 좋은 UHF 대역의 기술적인 활용 가능성이 고조되면서 산업적으로 성공할 가능성이 더욱 커지고 있다. UHF 대역의 무선 태그의 생산 기술은 종래에는 GaAs 쇼트키 다이오드와 기타 RF회로를 CMOS 회로와 하나의 칩으로 통합하는 것이 어려워 저가, 초소형의 무선 태그용 칩을 실용화하지 못하였다 하지만 최근에 반도체 기술의 눈부신 발전과 CMOS RF 기술의 발전으로 RF 태그용 무선회로를 하나의 칩으로 통합하여 저가 생산으로 특히 유통 및 물류 분야를 중심으로 긍정적인 활용 결과 및 제품들이 등장하고 있다.(중략)

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.403-403
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• 2004

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.504-506
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• 2008

전기전자 장치 내부의 PCB에 존재하는 전력공급/접지판은 RF 공진잡음을 발생시켜 디지틀 신호 품질 저하 및 불요방사의 문제를 일으킨다. 본 논문에서는, 전력공급/접지판의 RF 잡음을 제거하기 위한 방법으로 Mush-room EBG 구조를 사용할 때 이 구조가 가지는 전자기 및 전기적 특성을 모드해석법과 회로이론의 하이브리드화를 통해 예측을 수행한다. 예측을 통해 잡음을 억제할 수 있는 유용한 정보를 얻는다.

• The Journal of the Korea institute of electronic communication sciences
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• v.4 no.3
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• pp.183-189
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• 2009

In this paper, we propose RF front-end architecture using hybrid conversion method to receive broadband signal. The validity is verified by design, fabrication and experiment. The proposed RF front-end architecture due to up-conversion block improves the deficiency of performance deterioration to be generated through harmonic signal and image signal conversion in the conventional RF front-end, and improves the deficiency of the complexity that is from to adopt a multiple local oscillators for the generation of wideband LO signal in the conventional RF front-end by applying the principle that tuning bandwidth is multiplied at sub-harmonic mixer. Manufactured circuits satisfy the deduced design specification and target standard with gain above 80 dB, noise figure below 6.0 dB and IIP3 performance above -5.0 dBm for the condition of the minimum gain in RF front-end.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.10
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• pp.2194-2200
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• 2010

In this paper, the power detectors using metamaterials were designed and fabricated for multi-band six-port direct conversion method. The RF short-stubs for power detector were designed by using metamaterials which provide multi-band characteristics. The power detectors with metamaterial RF short-stub were analyzed and fabricated by using lumped and distributed element. The measured results of metamaterial power detectors show the good agreement with the simulation results. The performance of lumped-metamaterial RF short-stub shows the insertion loss below 1 dB and the good frequency response characteristics. Also, the distributed-metamaterial RF short-stub shows the good frequency response characteristics and the insertion loss under that of lumped-metamaterial RF short-stub. The multi-band power detectors with metamaterial RF short-stub detect the input RF signal in the designed dual frequency bands very well.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.2
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• pp.100-108
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• 2014

In this paper, we design SSD(simultaneous single band duplex) system using RF(radio frequency) cancellation and digital cancellation. we analyze characteristic of residual self-interference after RF Cancellation signal when error of phase shifter occur in RF cancellation. When phase shifter error of $0^{\circ}$, $0.5^{\circ}$, $1^{\circ}$ and $2^{\circ}$ occur in RF cancellation, residual self-interference signal power after RF cancellation is bigger than desired signal power of distant station. So, it is impossible to receive transmit data of distant station. but we confirm that it is possible to receive transmit data of distant station by digital cancellation with frame structure. Also, in digital cancellation with frame structure, if residual self-interference signal after RF cancellation is too large then LMS algorithm requires more time to estimate self-interference channel. That is, performance degradation occurs because self-interference channel estimation has not completed in estimation frame.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.11 no.6
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• pp.772-777
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• 2018

This paper used RF Magnetron Sputtering to deposition n-type and p-type to ITO glass. The N-type ohmic contact worked well under all conditions. Sheet resistance has been shown to increase sheet resistance as RF Power increases. After analyzing the surface of the deposited thin film, in the condition that RF Power was 250W and substrate temperature was $250^{\circ}C$, particles were measured to have a uniform and consistent thin film. P-type has good ohmic contact under all conditions and sheet resistance has been shown to increase as RF Power increases. As the RF Power grew, thickness increased and stabilized. PN junction thin film and NP junction thin film showed increased thickness and stabilized as sputtering time increased. As a result of thin film, conversion efficiency was at 0.2 when sputtering time was 10 minutes.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.1 s.4
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• pp.21-30
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• 2004

This paper describes the design of RF link between RSE and OBU of ETCS and the analysis of the antenna beam pattern to get a proper communication area in the cross direction and traveling direction of lanes. This stage should be performed prior to determination of system requirements of ITS service based on active DSRC. This study is important and fundamental technical analysis to design and implement base station of ETCS.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2007.06a
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• pp.682-684
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• 2007

This paper deals the application of sensor network system to fabricate wireless nodes. This node includes a CPLD(XC2C256), FPGA(XC3S1000) a RF module(Bim-433-F), a Hall Sensor and I also develop the CPLD(EPGA) controlling with Verilog-HDL using ISE. The network was consisst of a PC, a Sink node as a gateway, and three Sensor nodes. This sensor network can reaches 40 m with RF interface using by multi-path network.