• ETRI Journal
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• v.10 no.1
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• pp.32-38
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• 1988

CCITT No.7 신호방식은 향후 도래할 종합 정보 통신망에 적합한 공통선 신호 방식이다. CCITT No.7 공통선 신호 기능의 일부인 신호 연결제어부는 메시지 전달부(MTP)의 상위에 위치하여 다양한 서비스 정보 및 망운용에 필요한 정보를 전달하는 역할을 수행한다. 본고는 CCITT Red Book 이후 계속되어온 CCITT 회의 자료를 근거로 하여 신호연결제어부의 전반적인 기능을 소개하고 향후 TDX-10에 실현할 신호연결제어부의 기능들에 대해 기술하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.05c
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• pp.237-241
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• 2002

전력선과 조명등을 이용한 음향전달 시스템을 구성하여 어학실습 교육용으로의 활용 가능성을 평가하였다. 음성신호를 변조하여 전력선에 실어 보내는 송신기와 조명등의 빛으로부터 음성신호를 검출하여 이어폰 또는 헤드폰 둥으로 들을 수 있는 수신기로 구성하였다. 제작한 송신기와 수신기의 주파수 특성과 스펙트럼분석을 하였다. 스피커로 출력되는 음질상태는 최적상태는 아니지만 음성이나 노래 등을 이용한 어학실습 교육용으로는 충분한 수준이 었다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.3
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• pp.128-134
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• 2004

This paper presents a result of sound transmitting system with power line communication technique. Sound transmitting system is a transmitter which transmits modulated audio signal to power to power line and receiver which is capable of detecting it with earphone or speaker. It has been evaluated with the frequency characteristics and spectrum analysis. And, from the result of evaluation on the developed system, we confirmed the superior sound transmitting characteristics, and the possibility of application on a language laboratory.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.2
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• pp.61-66
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• 2011

A new via structure on printed circuit board has been proposed for differential signaling in applications of high-speed interconnection. In new structure, the via is physically separated and then divided into two electrically-isolated sections using mechanical drill routing process. These cutted vias are connected respectively to the traces of the differential pair. New via structure makes possible to rout the differential pair using only one via, while conventional via structure needs two vias for interconnection. Because the spacing even in via region keeps almost constant, new via structure can alleviate an impedance discontinuity and then enhance its signal transmission characteristics such as reflection loss and insertion loss. It is expected that new via structure is effective in differential signaling for high-speed interconnection.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.9
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• pp.47-53
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• 2011

The signal transmission properties of the connector such as insertion loss and return loss are investigated using analysis procedure of S-parameter simulation, equivalent model extraction, and characteristic impedance calculation. S-parameter simulation is performed by connector's modeling and solving based on 3-dimensional finite element method. The connector's equivalent model of ${\pi}$ type is are proposed and extracted with an optimization process of circuit analysis simulator. The characteristic impedance of the connector is calculated with results of circuit analysis simulation and S-parameter data. According to the connector's characteristic impedance, it's revised design is carried out. In this work, the connector's effective contact area is increased and its body is applied as a high dielectric material in order to increase its capacitance and then obtain impedance matching. Therefore, return loss of the connector is improved by approximately 10 dB due to its design revision.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.2
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• pp.165-172
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• 2019

Using two or more coaxial lines, if one port is connected in series and the other port is connected in parallel, it can be implemented the wideband transmission line transformer(TLT). Because the wideband TLT utilizes the outer conductor of the coaxial line, it is difficult to predict the characteristics. In this paper, based on the analysis for the transfer characteristic(S21) according to the loss of the each line in ${\lambda}/4$-microstrip line TLT, the operating characteristic of the fabricated wideband 4:1 TLT using two $25{\Omega}$-coaxial lines is investigated. The fabricated wideband TLT shows the notch characteristic in which the transfer signal sharply decreases at ${\lambda}/4$ frequency of the coaxial line and has a value within -0.2dB of the transfer characteristic(S21) in $0.06{\sim}0.2{\lambda}$ frequency range of the coaxial line. This transfer characteristics(S21) can change the operating frequency range slightly and set the optimum transfer characteristic(S21) at the desired frequency by changing the length of the microstrip line.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.1006-1009
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• 2015

Power-line communication technology is proposed to identify power transformers to serve customers in 3 phase -4 wires power distribution systems. Mathematical models for 3-phase power transformers, 3-phase wire lines, and customer loads are described to investigate the transmission characteristics of high frequency power line carrier. From the analysis, distribution line cable circuits have only a limited ability to carry higher frequencies. Typically power transformers in the distribution system prevent propagating the higher frequency carrier signal. The proposed method uses the limited propagation ability to identify the power transformer to serve customers. A novel power transformer identification system is designed and implemented. The system consists of a transmitter and a receiver with power-line communication module. Some experiments are conducted to verify the theoretical concepts in a big commercial building. Also some simulations are done to help and understand the concepts by using MATLAB Simulink simulator.

• KEPCO Journal on Electric Power and Energy
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• v.1 no.1
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• pp.85-91
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• 2015

We investigated the structure of inductive coupler and its magnetic coupling to increase the transmission coefficient for power line communication. A Rogowski coil, which is an air-cored inductive coupler, and a magnetic cored coupler were fabricated to analyze the transmission coefficient for different coupler parameters. This paper proposes the impedance matching method using lumped elements and an impedance transformer to increase the transmission coefficient. In the experiment, the transmission coefficient of the proposed system was increased in both narrowband and broadband cases, and a trade-off between the transmission coefficient and the bandwidth was shown. This method will be useful for the further study of impedance matching with the load variation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.10
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• pp.1282-1289
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• 2019

In order to measure the transfer characteristic(S21) of the impedance transformer, two impedance transformers must be symmetrically connected. However, the transfer characteristic of two symmetrically connected impedance transformers is influenced by the length of the intermediate connection line. This paper theoretically examines closely the length of the intermediate connection line to obtain the accurate transfer characteristic of the impedance transformer. The electrical length of the intermediate connection line for obtaining the accurate transfer characteristic of the 4:1(50-Ω:12.5-Ω) impedance transformer is calculated about 45°. Using the calculated length of the connection line, The λ/4-microstrip impedance transformer is fabricated at 1 GHz to measure the transfer characteristic. The symmetrically connected impedance transformer is measured the reflection characteristic(S11) of -40.64dB and the transfer characteristic(S21) of -0.154dB at 0.980GHz. This value is approximately equal to the theoretical calculated 987MHz center frequency and -0.15dB transfer loss value of the λ/4-microstrip impedance transformer.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.7
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• pp.786-795
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• 2010

In this paper, we propose a new EBG structure that the two unit cells are connected by the bridge line in signal transmission plane. The SSN of the power plane is reduced effectively by via holes and bridge lines connecting the unit cells. The superior signal transfer characteristic is shown between the signal lines in the signal transmission plane. The proposed EBG structure contains 1.2 GHz cut-off frequency and less than －30 dB suppression in the 8.3 GHz broad bandwidth. In addition, To improve the SI(Signal Integrity) in signal transmission plane keeping the same bandstop frequency range, the optimized location of the reference plane is proposed.