Design and performance of ultra-high-density optical fiber cable with rollable optical fiber ribbons

This paper proposes a novel ultra-high-density optical fiber cable that employs rollable optical fiber ribbons. The cable has great advantages in terms of cable weight and diameter, and fiber splicing workability. Moreover, it will be easy to install in a small space in underground ducts and on residential and business premises. The structural design of the rollable optical fiber ribbon is evaluated theoretically and experimentally, and an optimum adhesion pitch P in the longitudinal direction is obtained. In addition, we examined the performance of ultra-high-density cables with a small diameter that employ rollable optical fiber ribbons and bending-loss insensitive optical fibers. The transmission, mechanical and mid-span access performance of these cables was confirmed to be excellent.     

蝉对自承式引入光缆产生的损害及防护

简要叙述了国内外光纤到户(FTTH)的发展概况,分析了蝉对自承式引入光缆产生的损害,介绍了国外在自承式引入光缆防蝉方面的研究,讨论了国内当前自承式引入光缆的发展现状,最后为我国发展FTTH用防蝉光缆提出了一些意见和建议。     

NEXT and FEXT models for twisted-pair North American loop plant

Measurements of near-end crosstalk (NEXT) and far-end crosstalk (FEXT) in 26-AWG and 24-AWG polyethylene insulated cable (PIC) twisted pair cables are presented. This data is used to develop crosstalk models that indicate existing T1.417 Standard NEXT and FEXT models are probably conservative by about 5 dB for 25-pair binder groups. However, many cables start from wire centers as pulp cables of 100-pair binder groups. Even if most of these older pulp cables are 26-AWG, prudence dictates that a more conservative model be used for these cases. On a going forward basis for new and rehab construction, it should be recognized that PIC (air core and filled) cables with not larger than 25-pair binder groups are the predominant cable media supplied by manufacturers for feeder and distribution loops. Results for NEXT in 12-pair binders are also analyzed and show that 26-AWG cable has about 2 dB more NEXT loss than 24-AWG cable and 12-pair binders have about 2 dB more NEXT loss than 25-pair binders. In addition, the NEXT loss separation between adjacent binders of 12 and 13 pairs is found to be not more than 10 dB as compared with the more optimistic 15.5 dB assumed within the industry     

光纤光缆最新进展

本文对国内外光缆的最新进展进行了综合分析。针对国内现状,对大芯数光缆、接入网用光缆、ADSS光缆提出了若干建议。同时,还对涉及光纤光缆测量方面的一些新技术作了简单的介绍。     

Optical fibre cable with ultra-high density of more than 3 fibres/mm/sup 2/

Proposed is an ultra-high-density 100-fibre cable that uses 0.25 mm diameter mono-coated optical fibres with a low bending loss. This cable has great advantages in terms of cable weight and diameter and will be easy to install in a small space in underground ducts and/or on residential and business premises. The optical fibre with the optimum low bending loss is selected experimentally to obtain optical fibre cable with the maximum fibre density. A 100-fibre cable with a fibre density of more than 3 fibres/mm² and a cable diameter of 6.3 mm was obtained     

An overview of cable modem technology and market perspectives

Cable modem technology enables its users to access the Internet at line speeds of some 300 kb/s and above. It utilizes coaxial cables entering subscribers' premises to simultaneously deliver cable TV programs, access the Internet, and also provide voice telephony. This overview article describes the basic technology, its standardization, and the huge potential market worldwide     

Studies on designing of submarine optical fiber cable

This paper describes important studies necessary to design submarine optical fiber cables. These include a study for deciding the optimum single-mode fiber parameters to suppress losses during cabling, cable laying, and so on. It also includes a study on the necessary fiber proof test conditions to prevent fiber breakage during cable handling, that is, during cable laying and recovery and to assure long-term fiber reliability. Submarine optical fiber cable sea trial results are also stated for cables designed applying these studies.     

保护层结构对铁路信号电缆机械性能的影响

针对铁路信号电缆施工现场提出的加强铁路数字信号电缆机械性能的要求,主要研究了增强电缆保护层机械强度来提高铁路数字信号电缆机械性能的可行性。参考室外直埋式光缆的机械性能试验,根据铁路信号电缆施工现场的环境,提出了反映信号电缆机械性能的专项技术要求和试验方法。将新试制的保护层加强型信号电缆样品与既有的普通保护层信号电缆样品进行了机械性能的对比试验,试验结果表明,相比于相同型号的普通保护层信号电缆,保护层加强型信号电缆的机械性能提高不明显。     

Measurement of longitudinal strain in optical fiber cables during installation by cable ploughing

This paper reports a series of experiments in which a number of optical fiber cables were installed using cable ploughing equipment. The elongation of fibers in these cables was monitored during installation in order to assess whether excessive strain levels were encountered. The experiments confirmed that optical fiber cables can be satisfactorily installed using such techniques, and that residual strain levels were sufficiently low that the fiber lifetime was not prejudiced. It was found that optical fiber cables that are flexible and in which fibers are loosely housed can be installed with lower strain levels than other cables. A range of cable-ploughing equipment was used, and equipment which controlled the rate at which cable was fed from the cable drum was found to yield the best performance.     

新型高压电缆快速充气试验装置的设计

对原有的高压电缆气密性试验装置进行了技术缺陷分析,创新设计了一种新型的高压电缆快速充气试验装置,阐述了新型高压电缆快速充气试验装置的优点,并且对新研制的气密性试验装置进行了试验应用说明。     

Comparative Testing of Leaky Coaxial Cables for Communications and Guided Radar

Leaky coaxial cables are finding increasing use in communications systems involving mines, tunnels, railroads, and highways, and in new obstacle detection, or guided radar, schemes for ground transportation and perimeter surveillance. This paper describes the theory and operation of a new laboratory testing technique for these leaky cables based on a novel form of cavity resonator. The technique yields highly consistent and repeatable results that usefully assist in the prediction of the performance of full-size systems, from a simple test on a small sample of cable in a laboratory setting.     

The Submarine Optical Cable of the Submarcom S 280 System

Submarine optical telecommunication cables must satisfy a large number of specific items. To comply with specifications, CDL has developed a cable structure based on high-performance optical fibers placed with slack in the grooves of a plastic rod put in the center of a very strong cable. The deep-sea cable is the basic structure for armored cables or land cables. Armor transitions are designed to minimize cable twist. The couplings are designed to give a good optical electrical and mechanical continuity between the cable and the repeaters. The deep-sea repair is designed to be achievable on a cable ship. The cables, repairs, and couplings have successfully sustained several sea trials and two experimental links are now operating. No increase of the attenuation of the optical fibers in the cable have been noticed on the 19-month old first link. The development of the S 280 cable is proceeding on the right track.     

Emerging residential broadband telecommunications

Although near-term benefits are driving both telephone companies and cable operators to deliver residential services over optical fiber, in the longer term fiber enables new interactive, multimedia, switched “Information Age” services. The authors address residential fiber deployment, and opportunities for these two industries to work together in providing new services     

Organic outgassing behavior of plastic material and reduction of organic contamination in semiconductor equipment

We developed a low organic contamination (LOC ) electric cable as part of efforts to reduce organic contamination in semiconductor equipment. Our development strategies for LOC cables were obtained from the study of the behavior of outgassing from electric cables and the behavior of adsorption on silicon wafers. Strategy I: Reduce low boiling point organic contaminants from electric cables. Strategy II: Reduce organic contaminants with high adsorption rates on silicon wafers. Developing LOC cable under these two strategies, consequently, the amount of organic contaminants that are outgassed from the developed LOC cable was 1/10 or less of the level that is achieved by conventional cables. When compared with conventional cables, the flame-retardancy and flexibility are comparable. Then, we installed LOC cables in actual semiconductor equipment. The amount of organic contaminants adsorbed on the silicon wafer exposed in the equipment that was installed LOC cable and other low outgas parts were 1/6 lower than the conventional equipment. By using this low-outgassing cable in semiconductor equipment, we succeeded in reducing organic contamination in the equipment.     

一种新型低烟无卤高阻燃同轴电缆的研制

为满足成束阻燃同轴电缆的市场需求,研发了一种新型低烟无卤高阻燃同轴电缆,介绍了该电缆的结构设计、主要性能,并详细阐述该电缆关键材料的选择和电缆的制造工艺要点。     

抗水树交联电缆的设计和研发

抗水树电缆是未来中低压电缆的发展方向,本文论述了抗水树电缆的结构设计、原材料选用以及性能指标的确定,提出了电缆防水与抗水树相结合的全防水新概念。     

Prediction of Crosstalk in Ribbon Cables: Comparison of Model Predictions and Experimental Results

The prediction of crosstalk in ribbon cables is investigated. Experimental results are obtained for a 20-wire ribbon cable and compared to the predictions of the multiconductor transmission line (MTL) model. Based on the experimental configuration tested, it would appear that accurate predictions of crosstalk can be achieved in these controlled-characteristic cables. The prediction accuracies are typically within ±1 dB for frequencies such that the line is electrically short and ±6 dB for frequencies such that the line is electrically long. It was found that the parasitic wires in the cable can have a significant effect (as much as 40 dB) on the coupling between a generator circuit and a receptor circuit in the cable. Therefore, to achieve accurate predictions in ribbon cables, one must consider the interactions between all wires in the cable. The wire insulation evidently cannot be ignored for frequencies such that the line is electrically long. The impedance of the reference wire cannot be ignored for low frequencies where the common-impedance coupling dominates the electromagnetic-field coupling.     

Lightning current distribution to ground at a power line tower carrying a radio base station

Radio base stations are often mounted on towers of power transmission lines. They are usually powered from the low-voltage network through an isolating transformer, to separate the high- and low-voltage networks. The isolating transformer ensures security at customers' premises in the case of nearby power faults and particularly in case of lightning striking, which is a frequent cause of flashover of the high-voltage insulators and a subsequent phase-to-ground fault. To optimize such protection, a better understanding of the current distribution to the ground in the initial phase of the lightning striking is required. This work presents a computer simulation method and its results for the lightning current distribution between the sky wires, grounding systems, and power cable network. What is of special concern is the part of the lightning current that might be led into the metal-shielded distribution cable network. A rigorous electromagnetic modeling approach was applied for the analysis of the grounding effects in a network of coated and uncoated low- and medium-voltage cables. The analysis was then applied to a practical case.     

室内外两用中心管光纤带光缆

介绍一种室内外接入网两用的光缆 ,叙述这种光缆的设计与试验结果 ,说明它完全符合在室内外环境中使用的各项要求     

Model for estimating radiated emissions from a printed circuit board with attached cables due to Voltage-driven sources

Common-mode currents induced on cables attached to printed circuit boards (PCBs) can be a significant source of unintentional radiated emissions. This paper develops a model for estimating the amount of common-mode cable current that can be induced by the signal voltage on microstrip trace structures or heatsinks on a PCB. The model employs static electric field solvers or closed-form expressions to estimate the effective self-capacitances of the board, trace, and/or heatsink. These capacitances are then used to determine the amplitude of an equivalent common-mode voltage source that drives the attached cables. The model shows that these voltage-driven common-mode cable currents are relatively independent of the cable parameters and the trace or heatsink location when the PCB is small relative to the cable length and to a wavelength.