• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.138-138
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• 2004

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.14 no.4
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• pp.377-383
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• 2003

As the high-speed data communications such as xDSL using the existing copper cable come into wide use, the electromagnetic coupling characteristics of telecommunication cables become more significant. In order to describe the screening performance of telecommunication cable, the transfer impedance of cable shield is required. This paper describes the transfer impedance for two types of telecommunication cables using the line injection method of IEC 96-1. Results are analyzed to show how the materials of cable shields, the positioning of the injection line and of the inner conductor of the CUT(Cable Under Test) affect the value of transfer impedance. We then propose the transfer impedance model of telecommunication cable based on the measurements.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.1
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• pp.77-83
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• 2001

We analyzed the mechanism of EM emission in telecommunication system and extracted the dominant parameter in EMC design. The I/O cable, ventilation hole and shield design of chassis are important EMC design Issues in telecommunication systems. Because telecommunication systems have much more I/O cables than other electronic products, EMC design of I/O cable is very important in telecommunication systems. Therefore by the method of experimentation and simulation, EM coupling mechanism of I/O cable was analyzed and the design rule for low emission was extracted. On the base of these EMC design rules, EMC design of telecommunication system was executed without complex redesign or debug. The result obtained by these methods was shown in this paper.

• Korean Journal of Optics and Photonics
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• v.18 no.5
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• pp.333-336
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• 2007

A Strained Layer Multiquantum-Well (SL-MQW) distributed feedback laser at a wavelength of 1.31 um operating from $-40^{\circ}C$ to $85^{\circ}C$ without any cooling is grown by metal-organic chemical vapor deposition (MOCVD). Lasers with high slope efficiency are achieved through careful optimization of a SL-MQW active layer, especiallyoptimizing the amount of strain, the well thickness, the barrier thickness, the number of wells, and the active layer width. In this paper, we obtain the slope efficiencies of 0.38[mW/mA] and 0.26 [mW/mA] at $25^{\circ}C$ and $85^{\circ}C$, respectively. Threshold currents are 7.1[mA] and 19.8[mA] at $25^{\circ}C$ and $85^{\circ}C$, respectively.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.523-524
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• 2011

This paper covers induced voltage in parallel telecommunication cable with underground power cable to be linked between substations. The simulation was carried out the induced voltage in telecommunication cable according to the transposition of power cables and fault location for various conditions. This study based on the EMTP/ATPDraw with actual underground cable systems while the power cables are in steady state and transient state.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.10
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• pp.5148-5155
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• 2013

The induced voltage on the telecommunication cable generated by nearby electric railway system may bring about telecommunication errors and safety accidents. In order to reduce the induced voltage and to achieve communication reliability, the effect of the shield cables and the recent double-track railway systems on the inductive interference should be investigated. This paper analyzes the parameters which seriously influence the induced voltage on the telecommunication cables which run parallel with a AT-fed electric railway line, and provides a simulation-based approach to estimate the amount of the induced voltage. Simulation results indicate that the induced noise voltage generated by a double-track railway decreases by 18 % compared to that generated by a single-track railway, showing the screening effect by nearby track. The induced noise voltages on the 50%-shielded cable and 15%-shielded cable decrease to 1/8 and 1/15 of the induced voltage on the non-shielded cable, respectively. A meaningful shield effect is achieved and the induced voltage is minimized by the double-track railway and the shielded cable.

• Journal of electromagnetic engineering and science
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• v.1 no.1
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• pp.88-94
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• 2001

In this paper, the lightning-induced voltages on shielded twisted-pair wires with multipoint grounding on cable sheath are calculated by using finite-difference time domain (FDTD) method. The equivalent single-wire line that represents a bundle of twisted-pair wires is adopted for computational efficiency. A finitely conducting ground is also taken into account in both lightning electromagnetic field calculations and surge propagation along the shielded cable for a practical simulation. It is found that multipoint additional grounding on cable sheath provides more shielding effectiveness especially in the early time response of the lightning-induced voltages. From this study, the requirements for lighting surge protection devices in a telecommunication subscriber cab1e can be established.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1837-1839
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• 1998

This paper proposes the strain-insensitive temperature sensing in quasi-distributed sensor system using different thermal expension coefficient materials. This system has the high sensitivity and hasn't the necessity of reference signal. We can monitor the condition of the power cable with this system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.621-624
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• 2001

A metal sheath provides a cable with electrostatic screening and a degree of magnetic screening. The presence of a screen on a cable also reduces the induction arising from the high-frequency components of transients caused by power-line switching and also induced transients from lightning strokes; such transient induced voltages are of increasing importance with the increasing use of miniaturized telecommunication equipment with very small thermal capacity. This paper describes electrostatic induction and electromagnetic induction caused by power interference. Also screening factors are proposed.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.513-515
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• 2008

Due to the rapid development of telecommunication industry, most telecom operators are investing to upgrade their access networks by using optical cables instead of copper cables. Building new telecom ducts for optical cable installation requires so huge capital expenses that most telecom operators need to remove unused copper cables in order to secure enough space to in-stall optical cables. In this paper, we will present a alternative method to extract copper from removed copper cables.