• Title, Summary, Keyword: RF transfer

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Surface Transfer Impedance Measurement of RF Cable according to IEC Standard 96-1 (IEC Standard 96-1에 따른 RF 케이블의 표면전달 임피던스 측정)

  • 강진섭;김정환;강웅택;박정일
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.6
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    • pp.886-892
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    • 2000
  • In this paper, surface transfer impedance measurement of RF cables according to IEC(International Electrotechnical Commission) Standard 96-1 is described and surface transfer impedance of a commercial RF cable is obtained from the measured voltage and scattering parameter with a triaxial fixture fabricated in the operating frequency range from 1 MHz to 30 MHz.

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Highly Stable RF Transfer over a Fiber Network by Fiber-induced Phase Noise Cancellation (위상잡음 제거에 의한 광섬유망에서의 높은 안정도의 RF 전송)

  • Lee, Won-Kyu;Yee, Dae-Su;Kim, Young-Beom;Kwon, Taeg-Yong
    • Korean Journal of Optics and Photonics
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    • v.17 no.6
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    • pp.514-518
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    • 2006
  • We have transferred highly stable 100 MHz RF through a 23 km fiber network. The fiber-induced phase noise due to the vibration and the temperature fluctuation in the optical path is detected and is compensated by configuring a noise-canceling servo. The transfer instability was $6{\times}10^{14}$ at 1 s of averaging time and $2{\times}10^{-17}$ at 10000 s of averaging time. The single sideband phase noise was greatly reduced by more than 20 dB below the Fourier frequency of 1 kHz. The transferred RF has nearly the same stability as the original reference frequency.

RF Energy Transfer Testbed Based on Off-the-shelf Components for IoT Application (IoT 응용을 위한 RF 에너지 전송 테스트베드 구현 및 실험)

  • Aziz, Arif Abdul;Tribudi, Dimas;Ginting, Lorenz;Rosyady, Phisca Aditya;Setiawan, Dedi;Choi, Kae Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.10
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    • pp.1912-1921
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    • 2015
  • In this paper, we introduce a testbed for testing the RF energy transfer technology in the Internet of Things (IoT) environment, and provide experimental results obtained by using the testbed. The IoT environment considered in this paper consists of a power beacon, which is able to wirelessly transfers energy via microwave, and multiple sensor nodes, which makes use of the energy received from the power beacon. We have implemented the testbed to experiment the RF energy transfer in such IoT environment. We have used off-the-shelf hardware components to build the testbed and have made the tesbed controlled by software so that various energy and data transmission protocol experiments can easily be conducted. We also provide experimental results and discuss the future research direction.

A Development of 21' RF BAND ASS'Y BOX Transfer Loading System (21' RF BAND ASS'Y BOX 이송용 적재 시스템 개발)

  • Lee D.M.;Joo C.W.;Lee Sung-Hee
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.317-318
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    • 2006
  • A transfer loading system for 21' RF band assembly box was developed in the present study. The weight of a box is approximately 60kgf End total weight of one day job per person is about $4,000kg_f$. For an efficient design and manufacturing process, three dimensional design and engineering technique were applied to the presented system. Motion analysis for a popup unit and structural analysis for belt part subjected to the load of box weight were performed, respectively. It was found that the evasion of duty and labor intensity is reduced after appling the developed system to manufacturing field of small and midium business.

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Analysis of RF-DC Conversion Efficiency of Composite Multi-Antenna Rectifiers for Wireless Power Transfer

  • Deng, Chao;Huang, Kaibin;Wu, Yik-Chung;Xia, Minghua
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.10
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    • pp.5116-5131
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    • 2017
  • This paper studies the radio frequency to direct current (RF-DC) conversion efficiency of rectennas applicable to wireless power transfer systems, where multiple receive antennas are arranged in serial, parallel or cascaded form. To begin with, a 2.45 GHz dual-diode rectifier is designed and its equivalent linear model is applied to analyze its output voltage and current. Then, using Advanced Design System (ADS), it is shown that the rectifying efficiency is as large as 66.2% in case the input power is 15.4 dBm. On the other hand, to boost the DC output, three composite rectennas are designed by inter-connecting two dual-diode rectifiers in serial, parallel and cascade forms; and their output voltage and current are investigated using their respective equivalent linear models. Simulation and experimental results demonstrate that all composite rectennas have almost the same RF-DC conversion efficiency as the dual-diode rectifier, yet the output of voltage or current can be significantly increased; in particular, the cascade rectenna obtains the highest rectifying efficiency.

Physical Layer Secrecy Performance of RF-EH Networks with Multiple Eavesdroppers

  • Truong, Tien-Vu;Vo, Nhan-Van;Ha, Dac-Binh;Tran, Duc-Dung
    • Journal of information and communication convergence engineering
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    • v.14 no.3
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    • pp.171-176
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    • 2016
  • In this study, we investigate the physical layer secrecy performance of RF energy harvesting (EH) networks over Rayleigh fading channels. The RF-EH system considered here consists of one power transfer station, one source, one destination, and multiple passive eavesdroppers. The source harvests energy from the power transfer station and transmits the information to the destination by using a time switching-based relaying protocol. The eavesdroppers try to extract the transmitted information without an active attack. By using the statistical characteristics of the signal-to-noise ratio (SNR), the exact closed-form expressions of the existence probability of the secrecy capacity and the secrecy outage probability are derived. Further, we analyze the secrecy performance of the system with respect to various system parameters, such as the location of the system elements and the number of eavesdroppers. Finally, the equivalent Monte Carlo simulation results are provided to confirm the correctness of our calculations.

A study on remote video transmit technique of mobile phone (모바일폰에서의 원격 영상 전송 기술에 관한 연구)

  • Jeong, Jong-Geun;Kim, Chul-Won
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.10 no.10
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    • pp.1914-1919
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    • 2006
  • Video transfer problem on mobile is transfer speed and controls. Compression technique is needed to transfer videos and H.263 codec is used for compression, effectively controls camera on remote places, increased the real time connecting users. In this paper, we could solve the problem that use existent RF, and could transfer the most suitable image and audio.

Impact of Greenhouse Gas Emissions from Commercial Aircraft on Radiative Forcing and Temperature Change at the Airports in Korea: Comparison between Simplified Expression and Radiative Transfer Model (국내 공항의 항공기 온실가스 배출에 의한 복사강제력 및 기온변화 영향 연구: 배출량에 의한 추정식과 복사전달모델의 비교 분석)

  • Song, Sang-Keun;Shon, Zang-Ho;Jeong, Ju-Hee
    • Journal of Korean Society for Atmospheric Environment
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    • v.30 no.5
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    • pp.411-422
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    • 2014
  • In this study, spatial and temporal variations of radiative forcing (RF) and mean temperature changes due to greenhouse gases ($CO_2$, $CH_4$, and $N_2O$) emitted from commercial aircraft were examined based on the simplified expression at the airports in Korea during 2009~2010. The radiative transfer model (SBDART) was used to compare with the RF and mean temperature changes calculated from the simplified expressions for greenhouse gas $CO_2$. The RF simulated by the SBDART was about 67% higher than that of the simplified expression, on average. The highest mean RF (up to $9.0mW/m^2$ for $CO_2$) and mean temperature changes (up to $9.7{\times}10^{-5}^{\circ}K/day$ for $CO_2$) for all GHGs occurred at Ulsan airport during the study period, whereas the lowest RF and temperature changes at Yangyang (for $CO_2$) and Sacheon airports (for $CH_4$ and $N_2O$). In the case of $CH_4$ and $N_2O$, their effects to the RF and mean temperature change were negligible compared to $CO_2$.

Development of Skin Disease Smart Phone App. using CMOS Camera based on Hybrid RF (Hybrid RF기반 CMOS 카메라를 이용한 피부질환 모니터링 스마트폰 APP개발)

  • Lee, Minwoo;Park, Soonam;Lee, Nanhee;Lee, Junghoon;Lee, Jason;Shim, Dongha
    • Journal of Satellite, Information and Communications
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    • v.10 no.2
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    • pp.30-33
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    • 2015
  • In this paper, we proceeded a study on the Hybrid RF based development of the smart phone Application skin disease monitoring using CMOS camera. we proposed an image transfer technology which can use the CMOS camera and we developed the smart phone application which can be possible to use a remote monitoring for skin disease. Image transfer technology using Hybrid RF communication applied for WiFi using CMOS camera. We implemented the function which can use a remote monitoring using Wi-Fi. These suggestion can be a good example for endoscopic applications using hybrid RF based smart phone application of skin disease monitoring using CMOS camera.

Wireless Power Harvesting Techniques to Improve Time to Fly of Drone (무인항공기 비행시간 향상을 위한 무선 전력획득 기술)

  • Nam, Kyu-hyun;Jung, Won-jae;Jang, Jong-eun;Chae, Hyung-il;Park, Jun-seok
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.41 no.11
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    • pp.1574-1579
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    • 2016
  • This paper presents a self-powered sensor-node scheme using a RF wireless power harvesting techniques for improve drone time of flight. Sensor-node that is proposed is turned when two conditions satisfy: The one is input RF ID data from master-node should be same with sensor-node's ID, and the other one is RF wireless power harvesting system is turned on by hysteresis switch. In this paper, master-node's output is 26 dBm at 263 MHz. Maximum RF to DC power conversion efficiency is about 55% at 4-6 dBm input power condition (2 meter from master-node). The maximum RF wireless power harvesting range is about 13 meter form master-node. And power consumption of the sensor-node's load elements such as transmitter, MCU and temperature sensors is approximately average 15 mA at 5.0 V for 10 msec.